THE  SANITARY  RELATIONS 
OF  THE  COAL-TAR  COLORS 

LEFFMAN  N 


Columbia  ®nibersitp 
mtlieCitpoflmgork 

College  of  l^f)p&itian^  anb  ^uvQtoni 
mhvavp 


I 


THE 


COAL-TAR  COLORS 


WITH 


ESPECIAL  REFERENCE  TO  THEIR  INJURIOUS  QUALITIES 
AND  THE   RESTRICTION   OF  THEIR  USE 


A  SANITARY  AND  MEDICO-LEGAL  INVESTIGATION 

BY 

THEODORE    WEYL 

WITH    A    PREFACE    BY    PROFESSOR     SELL 

TRANSLATED  WITH    PERMISSION   OF  THE  AUTHOR 

BY 

HENRY   LEFFMANN,   M.D.,  Ph.D. 

PROFESSOR    OF    CHEMISTRY    IN   THE    WOMAn's    MEDICAL    COLLEGE    OF    PENNSYLVANIA,    AND 

IN     THE      PENNSYLVANIA     COLLEGE     OF      DENTAL     SURGERY; 

PORT    PHYSICIAN    AT    PHILADELPHIA 


PHILADELPHIA 

P.    BLAKISTON,    SON    &    CO 

IOI2     WALNUT     STREET 
1892 


Copyright,  1892,  by  P.  Blakiston,  Son  &  Co. 


QP9'1 


Press  of  Wm.  f.  Fell  &  Co.. 

1220-24  Sansom  St., 

philadelphia. 


TRANSLATOR'S  PREFACE. 


Dr.  Weyl's  essay  which  I  present  in  English  dress,  came  into 
my  possession  a  couple  of  years  ago,  and  seemed  to  me  to  be  of 
such  practical  value  in  an  important  department  of  hygiene,  that 
I  sought  permission  to  translate  it,  a  request  which  was  kindly 
and  promptly  granted  by  the  author.  The  widespread  employ- 
ment of  artificial  colors  in  articles  of  food  and  household  use 
and  the  absence  of  any  comprehensive  or  even  positive  informa- 
tion in  English  as  to  their  actions  on  the  human  system,  will 
make  the  publication  opportune. 

I  undertook  the  translation  over  a  year  ago,  but  the  close  ap- 
plication to  my  college  work  and  to  my  duties  as  Port  Physician 
of  the  Port  of  Philadelphia,  during  the  last  fall  and  winter,  has 
caused  considerable  delay. 

The  introductory  articles  by  Professor  Sell  and  Dr.  Weyl  ren- 
der an  elaborate  preface  unnecessary,  but  I  may  speak  briefly  of 
some  of  the  features  of  the  essay  which  will  be  more  likely  to 
suggest  themselves  to  an  American  than  to  a  European  reader. 

The  treatise  will  be  found  decidedly  more  technical  than  is 
usual  in  articles  addressed  to  medical  and  sanitary  circles  in  this 
country.  I  foresee  that  the  array  of  formulae  and  reactions, 
especially  the  ring  symbols  of  benzene  and  naphthalene,  may 
deter  many  from  perusal  of  the  essay,  yet  the  essential  matter  is 
so  distinctly  set  forth  that  the  chemical  portion  may  be  passed 
by  those  who  are  unable  to  comprehend  it.  I  have  deferred  a 
little  of  the  purely  theoretical  discussion  to  the  appendix ;  but, 
of  course,  I  have  not  felt  at  liberty  to  omit  any  appreciable  por- 
tion of  the  text. 

The  original  work  contains  numerous  references  by  foot-note 

iii 


IV  TRANSLATOR  S    PREFACE. 

to  original  authorities.  Since  these  are  accessible  to  few  readers 
in  this  country,  I  have  not  thought  it  necessary  to  repeat  the 
references  in  detail. 

For  the  more  accurate  and  satisfactory  representation,  I  have 
had  engraved  a  hexagon  matrix,  types  cast  from  which  have  been 
used  in  the  ring  symbols. 

It  will  be  a  source  of  gratification  to  the  practical  sanitarian  to 
note  the  comparatively  small  proportion  of  really  injurious  colors, 
for  even  with  some  of  those  which  produce  marked  toxic  symptoms 
such  large  doses  are  required  as  to  make  it  unlikely  that  serious 
results  could  occur  by  accident.  The  coloring  power  of  these 
bodies  is  so  high,  as  a  rule,  that  almost  inappreciable  proportions 
are  required  for  coloring  articles  of  food,  so  that  acute  effects,  at 
least,  are  impossible.  A  manufacturing  confectioner  of  this  city, 
for  whom  I  make  examinations  of  colors  used  by  him,  informs 
me  that  a  yellow  color  sold  as  auramine,  has  such  high  tinc- 
torial power  that  one  ounce  will  color  two  thousand  pounds  of 
candy  to  the  highest  yellow  tint  required  in  his  business.  It  is 
obvious  that  the  toxic  dose  of  such  a  body  would  have  to  be  very 
high  to  render  it  harmful  in  such  use. 

A  very  interesting  feature  of  the  present  essay  is  the  summary 
of  the  existing  legislation  on  the  topic  in  the  more  progressive 
countries  in  Europe.  We  have  here  presented  almost  every 
method  of  reaching  the  end  in  view,  viz.,  the  protection  of  the 
public  health  without  interfering  with  legitimate  trade  interests, 
from  the  practically  absolute  law-making  power  of  Germany 
based  on  imperial  will,  to  the  constitutional  system  of  England, 
with  its  reliance  on  the  merits  of  each  individual  case.  It  is  cer- 
tain that  none  of  the  plans  is  even  approximately  satisfactory, 
and  the  problem  will  be  even  more  difficult  of  solution  in  the 
United  States  ;  indeed,  it  seems  to  me  to  be  unsolvable.  Possi- 
bly the  simplest  and  most  satisfactory  method  would  be  to  forbid 
absolutely  the  use  of  any  artificial  color  in  certain  food  articles 
with  which  such  coloration  is  likely  to  deceive  the  user  as  to 
quality  or  condition,  and  to  require  in  all  other  cases  that  the 
name  and  amount  of  color  should  be  placed  on  the  package. 


TRANSLATOR  S    PREFACE-.  V 

Thus,  the  addition  of  color  to  milk,  butter,  cheese,  bread,  cake, 
noodles,  and  wine  should  be  absolutely  forbidden,  since  the 
object  of  such  addition  will  be  always  to  deceive  the  buyer  as  to 
the  quality  or  composition  of  the  material,  but  candies,  confec- 
tions and  toys  are  known  to  be  colored,  and  either  the  use  of 
certain  colors  and  none  others  should  be  permitted,  or  the  color 
used  should  be  required  to  be  indicated  on  the  package.  In 
this  connection  it  is  well  to  note  that  the  most  serious  reported 
cases  of  poisoning  from  colored  foods  have  been  those  in  which 
mineral  colors  were  used. 

The  knowledge  that  irritative  or  pathogenic  microbes  are  apt 
to  be  present  in  any  material  which  has  been  exposed  to  air, 
leads  us  to  regard  as  of  doubtful  value  all  those  experiments  in 
which  endermic  or  hypodermic  application  of  the  colors  was 
employed  without  antiseptic  precautions,  since  the  results  are 
complicated  by  such  infection.  This  is  doubtless  the  case  with 
the  observation  of  Tardieu,  on  the  poisonous  nature  of  corallin. 
The  preparation  made  from  the  stockings  was  more  poisonous 
than  the  original  dye,  because  it  was  infected,  as  would  naturally 
be  the  case,  with  more  virulent  organisms. 

In  the  preparation  of  this  translation  I  have  endeavored  to  be 
strictly  accurate,  and  yet  to  avoid  the  employment  of  forms  of 
expression  not  recognized  as  good  English.  Some  slips  will, 
however,  certainly  occur,  and  further,  I  cannot  hope  to  escape 
some  errors  in  transcription  or  composition.  For  all  such  I  ex- 
press my  regrets  in  advance. 

I  again  express  my  thanks  to  Dr.  Weyl  for  the  permission  to 
translate  the  essay,  and  hope  that  it  may  assist  in  diffusing  accu- 
rate information  on  a  topic  of  much  practical  sanitary  moment. 

H.   L. 

yij  Walnut  St.,  Philadelphia,  Augtcst,  j8g2. 


PREFACE. 


Most  civilized  communities  have  considered  it  advisable  to 
regulate  the  use  of  colors  in  food  preparations  and  other  house- 
hold articles.  It  appeared  to  me,  however,  after  much  investi- 
gation, that  the  experimental  basis  for  such  enactments,  notably 
as  concerns  coal-tar  colors,  is  insufficient,  indeed,  in  some  re- 
spects, wholly  wanting.  The  present  contribution  is  intended 
to  include  a  synopsis  of  such  information  as  was  already  attain- 
able, but  more  particularly  to  present  new  material  which  may 
have  valuable  bearing  on  the  framing  of  restrictive  laws.  Prac- 
tical application,  therefore,  is  the  especial  purpose  of  this  re- 
search. The  method  of  presentation  must  be  adapted  to  the 
fact  that  the  essay  is  addressed  to  both  physicians  and  chemists. 
Physicians  will  desire  some  general  views  of  the  chemistry  of  the 
colors,  since  this  part  of  the  subject  is  as  much  neglected  by  them 
as  the  principles  of  experimental  pathology  and  toxicology  are 
neglected  by  chemists.  I  trust  I  have  done  justice  to  each  class, 
in  that  I  have  not  been  too  medical  for  the  chemist,  nor  too 
chemical  for  the  physician.  In  exploring  along  the  contiguous 
territory  of  two  sciences  it  is  not  easy  to  escape  such  mistakes. 
The  collection  of  enactments  and  regulations,  as  far  as  accessible 
to  me,  will  be  found  useful.  The  names  and  properties  of  the 
colors  are  given  in  some  detail,  while  the  method  of  preparation 
is  but  briefly  outlined.  That  such  investigations  as  the  present 
are  rather  a  source  of  satisfaction  than  of  anxiety  to  the  color- 
making  industry  does  not  need  argument. 

I  offer,  therefore,  to  my  professional  brethren  far  and  near,  this 
first  contribution,  not  without  asking  for  myself  some  indulgent 
consideration  of  it,  by  reason  of  the  difficulties  attending  the 
task. 

My  thanks  are  due  to  C.  Liebermann,  E.  Salkowsky,  and  N. 
Zuntz,  for  affording  me  the  facilities  of  the  laboratories  under 
their  charge.  W. 

vii 


CONTENTS. 


VAGR 

History  and  Gkneral  Apfltcations, 17-22 

Preparation — Classification — Nomenclature — Commercial  forms 
— Uses — Dyeing,  Mordanting  and  Printing — Fastness — Detec- 
tion. 

Poisonous  Colors, 21-31 

Non-Poisonous  Colors, 31 

Laws  Regulating  the  Use  of  Poisonous  Colors, 31-34 

Appendix — Legal  Enactments  Co.xcerning  the  Use  of  Colors 

IN  THE  Preparation  of  Food, 35-53 

Germany — England — France — Italy — Austro-Hungary. 

Scope  of  the  Investigation, 53 

Methods, 54-60 

Selection  of  Colors — Selection  of  Animals — Manner  of  Adminis- 
tration— Diagnosis. 

Nitroso-Colors, ■  .    .    .        61-66 

Dinitroresorcinol — Naphthol  Green  B. 

NITRO-COLORS, 66-96 

Picric  Acid — Saffron-substitute — Mariius'  Yellow — Naphthol 
Yellow  S — Brilliant  Yellow — Aurantia — Other  Nitro-colors. 

Azo-CoLORs — Chemical  Considerations, 96-114 

-  Historical — Production — Materials  Employed,  Decompositions 
and  Transformations — Solubility,  Color,  Deportment  with 
Fibres — Typical  Reactions — Commercial  and  Scientific  Des- 
ignations— Classification. 

Observations  on  Animals, 114-134 

Records  from  other  Experimenters — Weyl's  Researches — Bis- 
marck Brown — Soudan  I — Metanitrazotin — Paranitrazotin — 
Orange  II — Ponceau  4  G  B — Archil-substitute — Chrysoidin — 
Diphenylamine  Orange — Metanil  Yellow — Azarin  S. 

ix 


X  CONTENTS. 

PAGE 

DiSAZO-COLORS, 134-137 

Fast  Brown  S— Wool  Black— Naphthol  Black  P— Congo  Red— 
Azo-Blue — Chrysamin  R. 

Conclusions, 147 

Appendix, 147-15 1 

Formation  of  Dve-stufts — Note. 


INTRODUCTION. 


Thanks  to  the  co-operation  of  theory  and  practice,  the  coal-tar- 
color  industry  of  Germany  has  conquered  the  world,  and  in- 
asmuch as  new  and  improved  methods  are  continually  being 
devised,  will  be  able  to  maintain  its  pre-eminent  position.  As  a 
result  of  this  steady  work,  we  find  thp  list  of  colors  constantly 
increased  by  new  products  which  enter  into  competition  with 
those  already  in  the  market. 

Consumption  must  stand  in  sgme  relation  to  production  if 
satisfactory  results  are  to  be  obtained,  and  trade  interests  stim- 
ulate endeavors  to  secure  new  uses  for  the  growing  supply.  It  is 
not  surprising,  therefore,  that  the  applicability  of  these  colors  to 
food  preparations  has  suggested  itself.  Whether  these  bodies  are 
adapted  to  such  uses,  and  whether  they  may  be  constantly  taken 
into  the  system,  even  in  small  doses,  without  disturbing  the  organ- 
ism, are  questions  of  great  moment  in  public  hygiene;  questions 
which  hitherto  could  not  be  answered,  for  want  of  satisfactory 
information.  For  this  reason  the  present  essay  of  Dr.  Weyl  is 
especially  welcome. 

The  author  has  made  a  valuable  contribution  toward  determin- 
ing the  physiological  relations  of  those  colors  applicable  to  foods, 
and  his  work  does  him  much  credit,  even  though,  as  he  points 
out,  experiments  on  animals  cannot  be  unreservedly  applied  to 
human  beings. 

An  especial  recommendation  of  the  work  is  that  the  author 
has  sought  to  discover  the  relation  between  chemical  composi- 
tion and  physiological  action,  an  undertaking  which,  carried  out 
fully,  may  make  it  possible  that  the  expert  will  be  enabled  to 
indicate  the  action  of  each  group  instead  of  that  of  individual 
colors. 

xi 


Xll  INTRODUCTION. 

Assured  that  the  author  himself  will  further  pursue  the  path  he 
has  opened,  a  hope  must  also  be  expressed  that  others  may  soon 
find  it  opportune  to  assist  in  the  difficult  work  of  this  investi- 
gation. 

Our  thanks  are  due  to  Dr.  Weyl,  not  only  for  presenting  to  us 
a  conspectus  of  the  most  interesting  features  of  each  group,  but 
also,  for  a  summary  of  the  existing  legislation  of  these  matters, 
in  the  principal  civilized  States  of  Europe. 

It  is  to  be  hoped  that  the  work  will  find  favorable  reception  in 
all  circles  which  are  interested  in  these  questions.  S. 

Berlin,  October,  i88S. 


THE  COAL-TAR  COLORS. 


GENERAL  PART. 

HISTORY  AND   GENERAL   APPLICATIONS. 

Preparation. — When  coal-tar,  the  source  of  the  coal-tar 
colors,  is  subjected  to  fractional  distillation,  products,  technically 
known  as  raw  materials,  are  obtained,,  among  which  are  benzene, 
toluene,  xylene,  naphthalene,  anthracene,  phenol  and  cresol. 
The  color-maker  transforms  these  into  intermediate  products,  and 
then  into  colors.  For  example,  from  benzene  and  toluene,  are 
obtained  by  the  action  of  nitric  acid  (nitration)  the  intermediate 
products,  nitrobenzene  and  nitrotoluene.  By  reduction,  aniline 
(amidobenzene)  and  toluidine  are  formed.  By  oxidation  of  a 
mixture  of  aniline  and  toluidine,  a  dye-stuff,  rosaniline,  is  pro- 
duced, which  belongs  to  the  aniline  colors  proper,  or  triphenyl- 
methane  derivatives.  So  also,  naphthalene — raw  material — 
yields  naphthol — intermediate  product — which  united  with 
diazobenzene  chloride — the  latter  obtained  from  aniline  by  the 
action  of  nitrous  acid — gives  rise  to  an  azo-color.  Phthalic  acid 
(intermediate  product)  united  with  another  intermediate  product, 
resorcinol,  forms  the  dye  called  fluorescein,  which  belongs  to 
the  phthaleins.  The  best  known  of  these  is  eosin — tetrabromfluo- 
rescein.  The  highly  important  dye  known  as  alizarin  is  derived 
from  anthraquinone,  the  latter  being  obtained  from  anthracene. 
Other  classes  of  colors  have  also  been  recognized,  such  as  safran- 
ins,  indamines,  indophenols,  etc. 

Classification. — The  various  colors  were  at  first  merely 
designated  as  red,  green,  yellow,  etc.,  coal-tar   colors.     Later 

2  17 


1 8  THE    COAL-TAR   COLORS. 

they  were  named  according  to  source,  as  aniline,  phenol,  and 
naphthol  colors.  Subsequent  research  has  elucidated  the  atomic 
structure,  and  rendered  possible  a  classification  in  natural  groups 
based  on  the  chemical  constitution.  The  following  are  some  of 
the  most  important  groups,  with  examples  of  each : 

I.     Nitroso-colors.     Naphthol  green  B,  solid  green. 
II.     Nitro-colors.     Picric  acid,  Martins'   yellow,  naphthol 
yellow  S,  aurantia. 

III.  Azo-colors.    Aniline  yellow,  Bismarck  brown,  Biebrich 

scarlet,  fast  yellow,  fast  red,  tropaeolin. 

IV.  Triphenylmethane  colors  (anilines,  properly  so  called), 

fuchsin,  malachite  green,  Victoria  green. 
V.     Rosolic  acid  colors.     Corallin,  rosolic  acid. 
VI.     Phthalein  colors.     Eosin,  erythrosin. 
VII.     Anthracene  colors.     Alizarin,  alizarin  orange. 
VIII.     Indigo  colors.     Indigo. 
IX.     Quinoline  colors.     Quinoline  yellow,  cyanine,  chrys- 

aniline. 
X.     Indophenol  colors.     Methylene  blue. 
XI.     Azine  colors.       Safranin,  magdala  red. 
XII.     Aniline  black. 

The  characteristics  of  these  groups  will  be  given  in  the  Special 
Part.  These  dyes  deport  themselves  in  part  as  acids  (acid  dyes), 
partly  as  bases  (basic  dyes),  and  in  part  as  indifferent  bodies 
(neutral  dyes).  Indigo  belongs  to  the  last  group.  Among  the 
acid  colors  are  the  nitrated  and  sulphonated  bodies,  such  as  pic- 
ric acid,  oranges,  ponceaux,  and  all  nitro-colors.  Basic  colors 
are  salt-like  combinations  of  color  bases  with  acids,  e.  g.,  fuchsin 
and  methylene  blue,  and  are  precipitated  by  tannin  or  picric  acid 
in  the  presence  of  sodium  acetate.  Acid  colors  are  mostly  in- 
soluble in  water,  but  dissolve  in  alkalies. 

Nomenclature. — The  trade  names  of  the  coal-tar  colors  are 
mostly  fanciful,  since  the  scientific  titles  are  cumbersome  and 
difficult  to  remember.  Thus,  tetramethylthionine  hydrochloride 
is  called  methylene  blue ;  aurantia  is  hexanitrodiphenylamine  ; 
wool-black  is  the  sodium  salt  of  sulphazosulphobenzeneparazo- 


HISTORY    AND    GENERAL    APPLICATIONS.  I9 

tolyl-/?-amidonaphthalene.  A  color  may  have  various  names : 
crocein  orange,  ponceaux  4  GB,  and  brilliant  orange,  are  iden- 
tical. The  terms  Bismarck  brown,  phenylene  brown,  Manches- 
ter brown,  and  canelle,  refer  to  the  same  color.  Different 
colors  are  often  designated  by  the  same  name,  especially  with 
a  view  of  substituting  a  cheap  for  a  costly  product.  In  this 
way,  according  to  Kertesz,  the  low-priced  Martius'  yellow  is 
called  naphthol  yellow  S,  although  the  latter  name  belongs  to  a 
more  expensive  preparation.  Finally,  mixtures  of  familiar  colors 
necessary  to  produce  peculiar  tints  are  frequently  sold  under 
new  names,  with  deceptive  intent.  Cardinal,  for  example,  is  a 
mixture  of  chrysoidin  and  fuchsin. 

Commercial  Forms. — Coal-tar  colors  are  offered  by  dealers 
either  in  the  form  of  paste  or  powder.  They  may  be  soluble  in 
water  or  alcohol,  or  both.  Insoluble  colors  find  obviously  but 
limited  application,  but  it. has  become  possible  by  special  treat- 
ment to  render  them  soluble.  This  takes  place,  for  instance,  by 
the  action  of  sulphuric  acid  (sulphonation),  or  when  azo-colors 
are  converted  into  bisulphites.  The  commercial  colors  are  often 
mixed  with  dextrin,  sodium  sulphate,  sodium  carbonate,  or  am- 
monium chloride.  This  so-called  coupage  (reduction)  is  rarely 
done  with  fraudulent  intent,  but  generally  for  one  of  the  follow- 
ing reasons : — 

The  method  of  preparing  a  color  does  not  always  yield  the 
same  tint ;  the  product  may  be  now  lighter,  now  darker,  perhaps 
due  to  slight  differences  in  the  temperature  during  the  process, 
or  in  the  subsequent  drying.  Since,  however,  the  dyer  requires 
that  a  certain  color  shall  yield  a  definite  shade  when  a  given  pro- 
portion is  employed  on  the  fabric,  the  manufacturer  must  reduce 
the  strength  of  the  more  highly-colored  product.  Furthermore, 
the  dyer  is  accustomed  to  employ  considerable  weight  of  the 
materials,  since  it  involves  less  variation  from  loss  or  error  when, 
for  example,  2000  to  2050  grams  are  employed,  than  when  only 
from  100  to  no  are  to  be  weighed  out.  Hence  the  manufacturer 
reduces  considerably  the  strength  of  the  dyes  of  high  coloring 
power.     Finally,  the  prices  may  be  made  lower  for  the  more 


20  THE    COAL-TAR   COLORS. 

extensively  diluted  articles.  In  general,  the  coal-tar  color-maker 
strives  to  furnish  pure  articles,  and  we  must  not  forget  that  small 
admixtures  of  foreign  substances  are  unavoidable.  The  traces  of 
salt,  lime,  etc.,  are  without  significance.  Injurious  impurities, 
such  as  arsenicum,  lead,  etc.,  are  scarcely  found  at  the  present 
time  in  coal-tar  colors  of  German  manufacture. 

Uses. — The  natural  colors  formerly  employed  by  the  dyer, 
have  gradually  given  way,  in  great  part,  to  the  more  convenient 
and  cheaper  artificial  products.  There  are  hardly  any  dyed  ma- 
terials now  in  the  market  in  which  coal-tar  colors  are  not  used. 
Of  course,  their  prime  use  is  in  dyeing  the  textiles,  silk,  wool, 
cotton,  hemp,  etc.,  but  they  are  largely  used  to  color  various 
other  animal  and  vegetable  products,  among  which  may  be  men- 
tioned, hair,  feathers,  leather,  bone,  ivory,  wood,  straw,  leaves, 
flowers,  paper,  soap,  and  ink.  Finally,  foods,  such  as  butter, 
cheese,  noodles,  confectionery,  wines  and  liquors,  are  colored 
by  these  bodies.  The  staining  of  microscopical  preparations 
by  means  of  coal-tar  colors  has  been  of  great  value  in  scientific 
investigations. 

Dyes  that  are  absorbed  directly  by  the  fibre  are  called  sub- 
staiitive  dyes;  among  these  are  fuchsin,  safranin,  and  Bismarck 
brown.  Those  that  require  the  fibre  to  be  impregnated  with 
some  substance  are  known  as  adjective  dyes.  The  material  used 
is  called  the  mordant,  and  its  action  is  due  to  the  formation  of 
an  insoluble  compound  between  the  fabric  and  the  color.  When 
a  metallic  salt  is  used  as  a  mordant,  the  insoluble  compound  is 
called  a  lake.  Among  the  familiar  mordants  are  lead,  copper, 
and  chromic  acetates,  alum,  zinc  chloride,  and  tartar  emetic. 
Turkey-red  oil — produced  by  the  action  of  sulphuric  acid  on 
castor  oil — tannin,  starch,  and  white  of  ^gg  are  frequently  used. 
Mordants  are  important  in  the  dyeing  of  vegetable  fibres, 
notably  cotton.  Recently,  however,  some  azo-colors  belonging 
to  the  Congo-red  group  have  been  obtained,  which  give  fast 
colors  on  cotton  without  mordanting. 

Dyeing,  Mordanting,  Printing. — The  dyeing  of  textiles 
depends,  as  is  generally  known,  upon  the  production  of  a  chem- 


HISTORY    AND    GENERAL    APPLICATIONS.  21 

ical  combination  between  the  color  and  the  fibre.  A  given 
color  does  not  necessarily  color  all  fibres.  Cotton  is  not 
dyed  by  alkali  blue,  naphthol  yellow,  or  acid  magenta, 
while  silk  is  easily  colored  by  them.  Picric  acid  dyes  animal 
fibres  readily,  but  can  be  attached  to  vegetable  fibres  only  by 
the  aid  of  a  mordant.  Textiles  can  be  dyed  either  in  the  yarn 
or  in  the  piece.  For  printed  goods  the  procedure  is  as  follows : 
The  color  is  mixed  with  starch  paste,  tragacanth,  or  some  other 
suitable  thickening  material,  the  mordant  being  often  incorpor- 
ated at  the  same  time.  The  mixture  is  imprinted  on  the  goods 
by  means  of  rollers,  and  the  tissue  subsequently  steamed,  by 
which  the  insoluble  compound  between  the  fabric  and  dye  is 
formed  ;  this  then  will  remain  after  rinsing  and  soaping.  Pat- 
terns can  be  produced  upon  cloth  in  two  ways.  Either  the 
proper  portions  of  the  tissue  are  protected  by  the  imprinting  of 
materials  which  prevent  the  dye  from  adhering,  which  method  is 
known  as  reservage,  or  the  entire  cloth  is  dyed,  and  then  cer- 
tain portions  are  removed  by  the  application  of  some  decolor- 
izing material,  this  latter  method  being  known  as  enlevage. 
These  methods  are  especially  applicable  in  calico  printing. 

Fastness. — A  color  is  said  to  be  *'fast"  when  it  is  un- 
affected by  various  external  influences.  Obviously,  this  quality 
concerns  especially  the  dyed  colors.  The  dyer  recognizes  colors 
as  fast  to  light,  to  washing,  to  moisture,  to  scouring,  to  the  action 
of  soap,  acids,  and  alkalies.  Nearly  every  organic  color  is  more 
or  less  rapidly  bleached  by  light.  Wool,  for  instance,  dyed  with 
picric  acid  acquires,  after  a  few  days'  exposure  to  light,  a  brown- 
ish tint,  while  alizarin  is  one  of  the  fastest  of  colors.  Alizarin 
blue  and  Congo  red  are  almost  perfectly  fast  to  washing,  when 
on  cotton,  while  eosin  is  easily  removed  by  the  same  means. 
Fastness  to  scouring  concerns  such  articles  as  require  treatment 
with  alkaline  solution,  e.  g.,  stale  urine  mixed  with  ammonium 
carbonate.  By  such  treatment,  oil  and  gelatin  are  removed, 
and  a  felting  of  the  fibres  brought  about.  Acid  green  is  toler- 
ably fast  to  scouring ;  still  better  are  alizarin  blue  and  rosaniline 
blue. 


2  2  THE    COAL-TAR    COLORS. 

Detection. — The  recognition  of  the  coal-tar  colors  on  fabrics 
and  in  food  offers  so  many  difficulties,  in  many  cases  at  least, 
that  even  expert  chemists  are  not  always  able  to  get  satisfactory 
results.  The  difficulty  originates  partly  in  the  fact  that  there  are 
a  great  number  of  these  colors,  partly  because  the  amount  of  color 
used  is,  as  a  rule,  owing  to  the  high  tinctorial  power,  very  small. 
It  is,  therefore,  best  in  such  investigations  to  employ  consider- 
able amounts  of  the  material  to  be  tested. 

For  methods  of  recognizing  the  various  colors,  see  the  Special 
Part  of  this  work  and  the  authorities  cited. 


POISONOUS  COLORS. 
Non-poisonous  coal-tar  colors  may  be  rendered  injurious  by 
admixture  with  poisonous  substances.  Medical  literature  fur- 
nishes us  with  an  imposing  array  of  cases  of  poisoning  by  ^^ani- 
line  colors,"  in  most  of  which  fuchsin  or  similar  colors  are 
concerned.  When  the  manufacture  of  aniline  colors  was  first 
introduced,  toward  the  close  of  the  sixth  decade  of  this  century, 
the  poisonous  quality  of  these  bodies  was  unquestioned,  in  view 
of  their  derivation  from  so  poisonous  a  body  as  aniline.  It  was 
natural  to  assume  that  the  deleterious  properties  of  the  parent 
substance  should  be  transmitted  to  the  derivatives.  The  first  ani- 
line color  manufactured  on  the  large  scale  was  mauve'in,  which 
Perkins  prepared  in  1858.  Fuchsin,  discovered  by  A.  W.  Hof- 
mann  in  1858,  was  the  second  color,  and  was  first  made  on  a  com- 
mercial scale  by  Verguin,  in  Lyons,  in  1859.  ^^  ^^^^  ^^^^  ^  ^^^^ 
of  the  color  was  worth  about  1200  marks;  in  1866,  50  marks. 
The  first  investigations  into  the  effect  of  fuchsin  and  its  congeners 
upon  the  animal  organism  seem  to  have  been  made  by  Sonnen- 
kalb.  The  colors  examined,  aniline  red  and  aniline  blue  on  silk, 
and  fuchsin,  were  found  to  be  non-poisonous.  Sonnenkalb,  how- 
ever, pointed  out  that  they  might  become  poisonous  by  reason  of 
impurities  such  asarsenicum  and  mercury,  which  were  employed 
in  the  process  of  manufacture.  To  such  impurity  he  ascribed  the 
case  first  reported  by  Friedrich  and  subsequently  so  frequently 


POISONOUS   COLORS.  23 

quoted,  of  apparent  poisoning  in  a  young  man  who  was  for  two 
months  engaged  in  packing  anihne  colors,  Lyons  blue,  light  blue, 
and  fuchsin  Nos.  i  and  2.  I  doubt  if  this  case  was  due  at  all  to 
the  work  in  which  the  patient  was  engaged. 

Sonnenkalb  confirmed  the  correctness  of  the  general  opinion 
as  to  the  poisonous  nature  of  arsenical  fuchsin.  In  this  category 
belongs  also  the  case  of  poisoning  by  arsenical  fuchsin  observed 
by  Clemens,  in  which  a  girl  engaged  in  embroidery  work  per- 
mitted the  red  silk  thread  to  glide  constantly  over  the  same  point 
on  the  finger  until  a  narrow  incised  wound  in  the  skin  was  de- 
veloped, from  which  arose  phlegmonous  inflammation,  which 
spread  over  the  hand  and  forearm. 

In  consequence  of  the  fact  that,  about  the  year  i860,  it  became 
known  that  many  French  wines  were  being  extensively  colored 
with  fuchsin,  the  French  investigators  were  especially  active  in 
studying  the  effects  of  this  dye  on  the  animal  organism.  In  the 
experiments  of  Clouet  and  Bergeron,  dogs  were  found  to  bear 
without  injury  daily  doses  of  20  grams  of  fuchsin,  and  a  man 
took  in  the  course  of  a  week  a  total  of  3.5  grams  without  noting 
any  inconvenience.  Clouet  and  Bergeron  therefore  regarded 
fuchsin  as  harmless.  It  is  uncertain  whether  the  fuchsin  em- 
ployed by  Feltz  and  Ritter,-'"^  which  gave  rise  to  diarrhoea  and 
albuminuria,  was  pure. 

As  is  known,  Coupler  f  discovered  a  method  of  making  fuchsin 
without  the  use  of  arsenic  acid  or  mercuric  oxide,  by  employing 
nitrobenzene,  which,  although  very  poisonous,  is  volatile  and  can 
be  easily  driven  off.  Grandhomme  fed  two  rabbits  for  several 
weeks  with  fuschin  prepared  by  the  Coupier-Briining  method, 
administering  daily  0.5  gram  with  50  grams  of  barley.  The 
animals  remained  in  good  health  and  the  urine  contained  no 

*In  Cazeneuve's  work,  p.  43,  is  a  review  of  what  seems  to  be  rather  an 
inexpert  research  by  Poincare  oai  the  effect  of  various  coal-tar  colors  on  the 
animal  organism. 

f  The  Coupier-Briining  fuchsin  was  for  some  time  called  "nitrobenzene 
fuchsin." 


24  THE    COAL-TAR    COLORS. 

albumin.  After  an  interval,  15  grams  of  fuchsin  and  15  grams  of 
barley  were  mixed  and  fed  during  two  weeks.  No  disturbance  in 
the  condition  of  the  animals  was  noted.  Subcutaneous  injection 
of  a  one  per  cent,  solution  once  or  twice  daily  had  also  no  effect. 
Similarly,  a  hen,  which  had  eaten  for  three  weeks  oats  colored 
with  fuchsin,  was  in  good  health.  In  entire  accord  with  all  in- 
formation concerning  the  harmlessness  of  pure  fuschin  are  Grand - 
homme's  interesting  observations  among  the  workmen  of  the 
Hochst  Color  Works.  In  the  fuchsin  department,  52  workmen 
were  employed,  of  whom — 

6  had  been  working  there  from  3  to    4  years. 
6         "  "  "  4  '<    6      " 

II         "  "  "  6  "  10      " 

5         "  "  "II   "  18      " 

None  of  these  men  suffered  either  from  diarrhoea,  colic,  or 
disturbance  of  the  urinary  secretion,  although  daily  breaching 
the  fuchsin  dust.  Tests  of  the  urine,  made  on  Saturday  evening 
after  the  entire  week's  work,  showed  absence  of  albumin.  Fur- 
ther, investigations  as  to  the  effect  of  pure  fuschin  in  cases  of 
heart  and  kidney  disease  showed  the  entire  harmlessness  when 
taken  into  the  stomach. 

Finally,  it  is  now  and  then  asserted  that  skin  diseases  have 
been  brought  about  by  garments  dyed  with  fuchsin  and  similar 
colors.  In  the  notice  of  Bruce's  case — cutaneous  eruption  fol- 
lowing the  wearing  of  a  red-dyed  chest- protector — no  account 
is  given  of  any  chemical  examination  of  the  color.  The  case 
of  skin  disease  reported  by  Viand-Grand-Marais,  of  Nantes, 
which  appeared  during  the  wearing  of  an  amaranthine  and 
violet-colored  woolen  shirt,  was  ascribed  to  a  dye  which, 
according  to  the  authority,  showed  by  Marsh's  test  only  small 
amounts  of  arsenic. 

The  above  facts  justify  the  view  that  pure  fuchsin  is  non- 
poisonous  :  the  poisonous  action  of  the  commercial  color  is  due 
10  arsenical  compounds.  According  to  Grandhomme,  aniline 
blue,  aniline  violet  (dahlia),  and  malachite  green  are  also  non- 
poisonous. 


POISONOUS   COLORS.  25 

A  similar  statement  seems  to  apply  to  corallin.  Tardieu  re- 
garded this  as  poisonous.  It  is  produced  by  heating  phenol  with 
oxalic  and  sulphuric  acids  "  to  120-130°  C."  The  crude  melt, 
which  presents  itself  as  a  dark  red  resinous  mass  with  metallic 
lustre,  is  known  as  yellow  corallin.  The  pure  color  obtained 
from  yellow  corallin  is  called  aurin.  On  account  of  their 
fugitive  character,  red  and  yellow  corallins  are  not  much  used 
in  dyeing,  but  are  employed  in  the  printing  of  calicoes  and 
woolens.  Red  corallin,  also  known  as  pseonin,  is  produced  by 
treatment  with  ammonium  hydroxide  under  pressure.  Tardieu, 
has  reported  eight  cases  in  which  the  wearing  of  stockings  dyed 
with  corallin  was  attended  by  the  development  of  a  vesicu- 
lar eruption.  He  undertook,  in  conjunction  with  Roussin, 
two  series  of  experiments.  In  the  first,  red  corallin  obtained 
from  Persioz,  was  injected  into  the  stomach.  The  majority 
of  the  animals  died.  In  the  second  series,  Tardieu  used  the  ex- 
tract from  the  suspected  stockings.  The  animals  died  more 
quickly  than  in  the  first  series.  Weickert  pointed  out  that  the 
corallin  was  administered  in  alcoholic  solution.  The  post- 
mortem indicated  alcoholic  poisoning,  but  it  does  not  appear 
why  the  extract  from  the  stockings  was  the  more  poisonous. 
Moreover,  Weickert's  trustworthy  researches  have  proved  the 
entire  harmlessness  of  the  red  corallin  made  by  WiiVtz  of  Lieb- 
enau,  whether  administered  endemically,  hypodermically,  or  by 
the  stomach.  The  men  engaged  in  preparing  and  putting  up 
the  corallin  in  the  Wurtz  factory  were  in  good  health,  although 
the  skin  of  the  hands  was  intensely  colored.  From  these  facts 
it  appears  that  pure  corallin  is  non-poisonous.  In  all  proba- 
bility, the  eruption  that  attended  the  wearing  of  the  stockings 
was  due  to  an  arsenical  mordant.  The  German  law,  relating  to 
the  use  of  injurious  colors,  etc.,  restricts  the  use  of  arsenical 
mordants  to  such  proportions  as  will  give  not  more  than  0.002 
gram  to  100  sq.  cm.  of  the  finished  goods.  It  is  known  that 
the  workmen  in  color-printing  departments  are  most  likely  to  be 
affected.     I  may  note  some  observations  made  in  the  extensive 


26  THE    COAL-TAR   COLORS. 

cotton-spinning  and  printing  establishment  at  Zawiercie,  for- 
merly operated  by  A.  &  B.  Ginsberg,  for  the  report  of  which  I 
am  indebted  to  Mr.  Ginsberg,  of  Berlin.  Workmen  dealing 
with  sodium  arsenate  and  other  arsenical  preparations,  especially 
in  the  damp  rooms  of  the  dye-house,  in  which  they  worked  all 
day  in  wet  clothes,  suffered  from  swelling  of  the  hands,  feet,  and 
testicles.  Dermatitis  and  a  pock-like  eruption  occurred  which 
necessitated  removal  of  the  patients  to  the  hospital.  In  conse- 
quence, the  use  of  arsenical  mordants  was  discontinued  and 
without  disadvantage  to  the  operation  of  the  establishment. 
Landrin,  Babaut,  Bourgongnon,  Chevreul,  and  P.  Guyot  agree 
with  Weickert.  However,  it  seems,  as  Sell  has  pointed  out, 
commercial  corallin  occasionally  contains  phenol.  For  this 
reason,  the  German  law  of  July  5th,  1887,  places  corallin  among 
the  prohibited  colors.  According  to  Zulkowsky,  rosolic  acid 
(methyl-aurin)  is  obtained  by  the  oxidation  of  cresol  (mtthyl- 
phenol)  by  arsenic  acid,  in  the  presence  of  sulphuric  acid.  If 
this  method  should  be  actually  used,  as  to  which  I  have  no 
knowledge,  commercial  rosolic  acid  might  contain  arsenicum. 

In  this  connection,  the  remarkable  case  of  hyperidrosis,  re- 
ported by  Grandhomme,  should  be  mentioned.  In  the  Hochst 
dye-works,  at  various  times  from  1874  to  1882,  many  workmen, 
in  all  47,  most  of  whom  worked  in  the  eosin  department,  were 
affected  as  follows :  After  a  varying  period,  the  men  were 
seized  with  pain  in  the  finger  tips  and  ball  of  the  thumb,  and  in 
three  cases  abscesses  were  formed.  In  every  case  the  perspiration 
was  so  abundant  that  drops  fell  from  the  depending  hands. 
The  general  healtli  did  not  seem  to  be  disturbed  and  the  per- 
spiration showed  no  abnormality  either  in  odor  or  appearance. 
Recovery  took  place  in  about  sixteen  days.  The  cause  of  the 
affection  is  not  definitely  known.  Possibly,  it  arises  from  some, 
as  yet  unknown,  admixture  in  the  material,  possibly,  from  the 
use  of  strong  chlorated  lime  solution  for  cleansing  the  hands. 
At  any  rate,  the  cases  have  become  less  frequent  since  the  use 
of  such  strong  solutions  has  been  interdicted.      The  eosin  itself 


POISONOUS   COLORS.  27 

cannot  be  the  cause,  since  those  engaged  in  packing  it  are  in  no 
wise  affected.  Dr.  P.  Seidler  has  kindly  communicated  to  me 
the  note  of  a  case  of  hyperidrosis  which  affected  a  chemist  of 
his  acquaintance!  The  patient  had  been  in  the  dye-works  of 
Bayer  &  Co.,  in  Elberfeld,  and  had  used  very  strong  chlorated 
lime  solution  for  cleaning  his  hands.  Grandhomme's  view  as  to 
the  cause  of  the  malady  is,  according  to  this,  confirmed.  I  am 
now  investigating  this  subject. 

A  critical  review  of  the  existing  literature  shows  that  trust- 
worthy evidence  of  poisoning  by  pure  aniline  colors  is  not  at 
hand.* 

In  all  probability,  the  cases  in  which  the  color  has  been  sus- 
pected, have  arisen  from  admixture  with  arsenical  compounds,  or 
the  use  of  arsenical  mordants.  The  following  additional  con- 
sideration confirms  the  view  as  to  the  harmlessness  of  pure 
anilines. 

The  general  condition  of  the  health  of  those  engaged  in  coal- 
tar  color  factories  weighs  against  the  harmfulness  of  these  colors. 
If  the  aniline  colors,  and  artificial  colors  in  general,  were  as 
poisonous  as  is  often  gratuitously  assumed,  those  engaged  for 
long  periods  in  the  manufacturing  or  handling  the  same,  or 
otherwise  brought  in  close  contact,  ought  to  be  frequently  affec- 
ted injuriously.  Of  course,  the  products  and  by-products  of  the 
processes  bring  about,  frequently,  both  acute  and  chronic  poison- 
ing. It  would,  indeed,  be  surprising  if  those  who  are  engaged 
in  the  manufacture  of  benzene,  nitro-benzene  and  similar  bodies, 
should  not  be  more  affected  by  them  than  those  who  may  have 
but  seldom,  perhaps  only  once,  even  seen  such  materials  as 
specimens  in  a  cabinet.  Nevertheless,  Grandhomme  states  that 
in  the  extensive  factory  at  H6chst-on-the-Main  the  proportion 
of  sick  among  those  who  are  concerned  in  manufacture  of  the 

*  For  a  small  number  of  cases  of  poisoning  by  picric  acid,  see  the  Special 
Part. 


28 


THE    COAL-TAR    COLORS. 


raw  material,  is  insignificant.     The  following  tables   are  from 
Grandhomme's  work : — 


Department  of 

No.  OF 

Men. 

Illness  Due  to 
THE  Work. 

Remarks. 

Factory. 

Number. 

Per  Cent. 

Nitrobenzene,  .    .    . 

Aniline, 

Anthracene,      .    .    . 

96 

116 
2 

5 

18 
0 

5-2 

15.5 
0.0 

r  No  nitrobenzene 
\      poisoning. 

Aniline  poisoning. 

Still  more  favorable  are  the  figures  relating  to  those  who  work 
at  the  actual  manufacture  of  the  aniline  colors  : — 


Illness  Due  to  Work. 

No.  OF 
Workmen. 

No.  of 
Years. 

Remarks. 

• 

Department. 

No.  of 
Cases. 

Percentage. 

Rosaniline,    . 

2 

2 

0 

Fuchsin,    .    . 

396 

9 

31 

7.8 

Skin  affections. 

Blue,      .    .    . 

120 

4 

I 

0.83 

Aniline  poisoning. 

Dahlia,      .    , 

88 

4 

0 

0.0 

Green,  .    .    . 

84 

4 

0 

0.0 

Eosin  (prin-  ~l 
cipally),    J 

112 

4 

27 

24.1 

Hyperidrosis. 

Even  this  small  percentage  has  been  reduced  materially  by  the 
introduction  of  hygienic  measures,  as  the  following  table  shows : — 


Years. 

No.  of 
Workmen. 

Illness. 

Remarks. 

No.  of 
Cases. 

Percentage 

1879 

1880 

1881 

1882 

325 
447 
508 
500 

13 

18 

17 

7 

4 
4 

3-3 
1-4 

Aniline  poisoning. 

((               (( 

POISONOUS   COLORS. 


29 


The  hygienic  provision  consisted  in  better  ve'ntilation  of  the 
work-rooms,  and  the  regulation  that  the  workmen  should  be 
allowed  more  frequently  to  go  into  the  open  air,  also  prohibition 
of  the  employment  of  chlorated  lime  solution. 

If  now  we  determine  the  percentage  of  sickness  among  the 
workmen  in  branches  of  industry  in  which  actual  poisons  are 
used,  we  find  that  the  statistics  of  the  aniline  industry  compare 
very  favorably. 

The  numbers  for  the  workers  in  aniline  have  been  determined 
from  the  following  statistics  given  by  Grandhomme  : — 


Diseases. 


Infectious  diseases, 

Diseases  of  nutriiion,  ..... 
"  "  circulatory  system,  . 
"       "    nervous  " 

"  "  special  senses,  ...  . 
"  "  respiratory  apparatus, 
"       "    digestive  " 

"      due  to  occupation,  .    .    . 

Not  otherwise  classified,    .... 


330 


Workers  in 
Alizarine. 

Workers  in 
Aniline. 

7 

35 

77 

172 

5 

12 

16 

56 

28 

63 

89 

288 

103 

339 

1060 


Therefore,  a  total  of  330  plus  1060  equals  1390  internal  affec- 
tions. Of  these  88  were  cases  of  poisoning  from  occupation, 
which  equals  6.;^  per  cent. 


Occupation. 

Percentage  of  Cases 
OF  Disease. 

Form  of  Affection,  Etc. 

Gilders, 

Zinc  white  workers,  .    .    . 
Phosphorus  makers,  .    .    . 
Mercury  miners,     .... 

2-3 
3-4 

Phosphorus  poisoning. 
Mercury              " 

30 


THE    COAL-TAR    COLORS. 


Occupation. 


Aniline  makers,      .    .    . 

Hat  makers, 

Glaziers, 

Blue  color  makers,  .  . 
Artificial  flower  makers, 
Arsenicum  miners,  .  . 
Sweinfurth  green  makers, 
Sugar  of  lead  makers,  . 
Potters,    .... 


Tin  workers. 


Type  founders,  . 
Tobacco  workers. 


Silver  miners, 
White  lead  makers. 


Percentage  of  Cases 

OF  DiSF.ASE. 


6.3 

7-5 

lO.O 

12.5 

15 
20 
20 
21 
25 
35 

35 

15  (male). 

45  (female). 

58 
68 


FoBM  OF  Affection,  etc. 


Aniline  poisoning  and  hy- 
peridrosis,  probably  due 
to  arsenicum. 

Mercury  poisoning. 

Lead  " 

Arsenical        " 


Lead  " 

it  (I 

J  Lead  and  arsenical 
\      poisoning.  . 

Lead  poisoning. 

Nicotine  poisoning. 

Lead  " 


Dr.  Coster  thus  expresses  himself  in  regard  to  the  general 
health  of  the  workmen  in  aniline  works  : — 

"  We  are  justified  in  saying  that  work  in  aniline-color  fac- 
tories, usually  regarded  as  very  injurious  to  health,  does  not,  in 
any  way,  involve  greater  dangers  than  belong  to  working  in 
factories  in  general,  apart  from  such  acute  effects  as  result  from 
sheer  carelessness." 

From  the  above  facts  it  follows  that  the  poisonous  qualities  of 
the  aniline  colors  are  not  manifested  among  those  who  manufac- 
ture them. 

It  remains  to  mention  a  (ew  colors  known  to  be  poisonous. 
The  injurious  character  of  picric  acid  and  its  salts  has  long  been 
known.      Cazeneuve   and    Lepine    pointed    out    the   poisonous 


LAWS    REGULATING    THE    USE    OF    POISONOUS    COLORS.  3 1 

nature  of  Martins'   yellow,  safranin,  and  methylene  blue  :*  and 
I   have   shown  the  same  for  dinitrocresol  (saffron-substitute). f 

NON-POISONOUS  COLORS. 

According  to  Cazeneuve  and  Lepine's  experiments  the  following 
are  not  poisonous  to  human  beings  and  dogs:  Naphthol  yellow  S, 
and  certain  azo-colors  employed  for  the  coloring  of  wine :  viz., 
orange,  ponceau  R,  purple,  and  solid  yellow. 

According  to  Grandhomme,  rabbits  bear  without  injury, 
fuchsin  free  from  arsenic,  and  other  triphenylmethane  derivatives 
(aniline  colors)  eosin,  erythrosin  and  orange.  Butter  yellow 
(dimethylamidoazobenzene)  produces  no  disturbance  in  rabbits. 
The  toxic  action  of  aurantia  is  in  dispute,  concerning  which,  see 
the  Special  Part. 

LAWS  REGULATING  THE  USE  OF  POISONOUS 

COLORS. 
In  spite  of  the  facts  recorded  in  the  preceding  pages,  which 
show  that  the  danger  of  poisoning  from  the  aniline  colors  has 
been  much  overrated,  at  least  as  far  as  our  present  knowledge 
extends,  most  civilized  countries  have  deemed  it  necessary  to 
enact  laws  against  the  employment  of  the  common  colors  in  the 
preparation  of  food,  drink  and  household  articles  generally. 
These  regulations,  as  far  as  obtainable  by  me,  are  presented  as 
an  appendix  to  this  chapter.:]:  All  these  various  legal  provisions 
have  the  same  purpose:   to   prevent  the  adulteration    of  food, 

*  Confirmed  by  P.  Ehrlich,  by  information  kindly  communicated  verbally. 
Compare  also  the  exhaustive  investigation  on  "Neurotropic"  colors  by  the 
same  authority,  Therap.  Monafsh.,  March,  1887. 

t  See  Zeit.  f.  angew.  Chem.  1888,  No.  12,  for  confirmation  of  my  results  by 
Gerlach. 

X  I  gladly  avail  myself  of  the  opportunity  to  express  my  sincere  thanks  to 
Messrs.^  Carnelutti,  of  Milan,  Otto  Hehner,  of  England,  and  E.  Ludvvig,  of 
Vienna,  for  furnishing  me  with  the  text  of  the  laws  concerning  their  respective 
countries. 


32  THE    COAL-TAR    COLORS. 

drink,  and  household  articles.  The  method  by  which  this  is 
reached  is  threefold. 

Germany,  France,  and  Austria,  enumerate  the  harmful  colors 
which  are  not  allowed  to  be  used.  England  places  a  penalty 
for  the  adulteration  without  stating  what  colors  are  to  be  con- 
sidered injurious.  Italy,  coincides  with  England  in  the  form 
of  the  law,  but  provides  that  the  determination  of  the  injurious 
articles  shall  rest  on  the  judgment  of  experts  appointed  by  the 
Secretary  of  the  Interior.  A  justification  for  these  laws,  of  course, 
cannot  be  denied.  A  little  consideration  will  show  that  the 
practicability  of  the  legal  provisions  is  as  unequal  as  the  sense  of 
equity  and  justice  which  finds  expression  in  them. 

The  English  law  imposes  a  fine  of  fifty  pounds  sterling  upon 
every  one  who  mixes  or  colors  food  with  any  injurious  ingredient. 
Subsequent  offenses  may  be  punished  with  imprisonment,  up  to 
six  months.  This  law  seems  to  give  satisfaction  in  England. 
At  least  Mr.  Otto  Hehner  writes  me,  under  date  of  July  3d,  of 
this  year:  ^'So  far  as  I  know,  no  case  has  come  unde*  this 
paragraph  of  the  law  of  1873,  since  its  enactment.  Aniline 
colors,  as  long  as  they  are  not  strongly  arsenical,  are  not  re- 
garded as  injurious.  Nor  do  any  special  provisions  exist  here 
(/.  e.  in  England)  concerning  the  use  of  poisonous  colors  in  the 
carpet-weaving  or  calico-printing  industries.  The  force  of  public 
opinion  and  publicity  is  so  great  that  no  one  would  dare  to 
employ  poisonous  colors." 

Unfortunately,  here  in  Germany,  we  cannot  rely  upon  the 
force  of  public  opinion,  nor  on  publicity,  in  matters  concerning 
the  adulteration  of  food.  We  cannot  regard  a  law  as  either  cor- 
rect or  practical  which  punishes  the  adulteration  of  food  without 
enumerating  those  ingredients  which  are  to  be  regarded  as  harm- 
ful. The  Austrian  law  seems  to  be  the  simplest :  The  various 
provisions  enumerate  those  colors  which  may  be  used  in  food,  and 
punish  every  dealer  who  has  in  his  factory  or  store  any  other 
colors,  no  matter  what  name  these  bear.  The  regulation  of 
May,  1866,  (see  Appendix)  is  indeed  difficult  of  execution.  How 
can  a  confectioner  be  held  responsible  for  the  employment  of  a 


LAWS   REGULATING   THE   USE   OF   POISONOUS   COLORS.  ^^ 

color,  the  harmfulness  of  which  was  not  known  at  the  time  of  its 
application  ?  On  the  other  hand,  no  objection  can  be  brought 
against  the  regulations  issued  on  May  ist,  1886,  nor  those  noted 
subsequently,  intended  to  meet  a  special  purpose.  The  regula- 
tion forbids  the  employment  of  any  color  prepared  by  chemical 
treatment  of  aniline  or  other  coal-tar  products.  This  enact- 
ment takes  away  the  least  doubt  that  the  Government  pro- 
hibits the  use  of  all  coal-tar  colors  for  the  purpose  under  con- 
sideration. The  basis  of  the  prohibition  is  entirely  in  accord- 
ance with  the  spirit  of  the  law.  It  is  the  sense  of  the  declara- 
tion that  there  are  many  coal-tar  colors  in  commerce  the  action  of 
which  on  the  human  organism  is  unknown  and  the  adulteration 
to  which  they  are  liable  suspicious.  Such  articles  should  not  be 
employed  in  the  preparation  of  food  and  drink. 

Austrian  regulations  are  the  most  radical  in  this  field.  It  is  to 
be  assumed  that  the  principle  which  has  as  yet  found  application 
only  through  executive  action  will  take  the  form  of  enactment. 
Less  severe  than  the  Austrian  law  are  those  of  France  and  Ger- 
many. The  German  law  forbids  the  employment  of  certain 
enumerated  colors  and  permits,  therefore,  the  use  of  those  not 
mentioned.  In  France  the  injurious  and  consequently  forbidden 
colors  are  listed  as  well  as  those  which  are  harmless  and,  there- 
fore, permitted.^  Without  doubt,  both  these  laws,  which  repre- 
sent the  results  of  toxicological  and  chemical  research  up  to  a 
certain  time,  have  been  of  much  service  to  public  hygiene.  As 
regards  the  effects  of  mineral  colors  on  the  human  organism,  we 
are  sufficiently  informed.  The  near  future  will  not  bring  forth 
material  changes  in  regard  to  these,  but  it  is  otherwise  with  the 
organic  colors.  Chemical  technology  moves  by  giant  strides : 
new  colors  are  brought  into  the  market,  and  no  inquiry  is  insti- 
tuted as  to  the  effect  on  the  human  body.  If  the  new  color  is 
more  beautiful  than  its  predecessor,  or  cheaper,  the  tradesmen 

*  The  regulations  by  the  magistrates  of  Milan,  advance  sheets  of  which 
were  sent  me  by  the  courtesy  of  Dr.  Carnelutti,  permit  the  employment  of 
certain  definite — that  is  to  say  enumerated — coal-tar  colors. 

3 


34  THE    COAL-TAR    COLORS. 

throw  the  older  color  to  one  side.  This  is  not  forbidden  by  law. 
The  dealer  is  allowed  the  employment  of  any  color  not  men- 
tioned in  the  regulations,  even  though  it  may  have  been  subse- 
quently proved  injurious.  A  characteristic  illustration  of  this 
point  may  be  found  in  the  proclamation  emanating  from  the 
Chamber  of  Commerce  of  Sonneberg,  This  body  recommends 
for  the  preparation  of  children's  toys,  three  colors,  the  poisonous 
character  of  which  I  can  demonstrate.  These  are  Martins'  yel- 
low, safranin,  and  Bismarck  brown.  Of  course,  the  Chamber 
of  Commerce  could  only  abide  by  the  law,  and  this  did  not 
allude  to  the  above  named  materials.  The  law  maker,  however, 
is  not  to  blame,  for  the  facts  to  which  I  refer  were  not  known  at 
the  time  the  law  was  prepared.  Obviously,  some  amendment 
must  be  brought  about.  This  can  be  done  either  by  forbidding 
the  use  of  all  coal-tar  colors  in  the  preparation  of  food  and  drink, 
or  by  following  the  plan  of  the  Italian  law  and  providing  for 
periodical  investigations  by  a  commission  of  chemists  and  physi- 
cians, to  determine  what  are,  and  what  are  not,  appropriate  colors 
for  such  uses.  Upon  the  reports  of  such  commission,  the  legisla- 
ture will  regulate  the  use.  Should  the  use  of  every  one  of  the 
colors  be  forbidden,  as  has  been  done  by  the  German  government 
in  the  case  of  the  coloring  of  wine,  the  problem  is  solved  in  the 
simplest  manner.  By  this  means  we  would  bring  about  the  same 
condition  that  prevails  in  Austria.  Many  serious  difficulties 
beset  the  carrying  out  of  the  second  plan.  A  commission  can 
only  act  to  advantage  when  it  subjects  colors  to  investigation 
before  they  come  into  commercial  use. 

Undoubtedly  the  whole  matter  must  undergo  a  revision,  prob- 
ably in  the  shape  of  a  general  poison  law  affecting  the  entire 
Empire.  I  will  return  to  a  discussion  of  this  topic  in  a  later  sec- 
tion of  this  treatise. 


APPENDIX. 


LEGAL   ENACTMENTS    CONCERNING    THE   USE   OF 

COLORS  IN  THE  PREPARATION 

OF    FOOD. 

Germany. 

I.  Laws  concerning  the  use  of  unwholesome  colors  in  the 
manufacture  of  food,  drink,  and  other  articles.     July  5,  1887. 

We,  William,  by  the  Grace  of  God,  Emperor  of  Germany, 
King  of  Prussia,  etc.,  order,  in  the  name  of  the  State,  in  accord- 
ance with  the  approval  of  the  Federal  Council  and  the  Imperial 
Diet,  as  follows  : — 

1.  Unwholesome  colors  are  not  permitted  to  be  used  in  the 
preparation  of  articles  of  food  and  drink  which  are  exposed  for 
sale.  Colors  which  contain  antimony,  arsenicum,  barium,  lead, 
cadmium,  chromium,  copper,  mercury,  uranium,  zinc,  tin,  gam- 
boge, corallin,  picric  acid,  are  unwholesome  in  the  sense  of  this 
Act.  The  Chancellor  of  the  Empire  is  empowered  to  set  forth 
exact  methods  for  determining  the  presence  of  arsenicum  and  tin. 

2.  Vessels,  wrappers,  or  covers  dyed  with  colors  referred  to  in  § 
I  are  not  to  be  used  for  holding  or  protecting  articles  of  food  or 
drink.  The  present  regulation  does  not  apply  to  the  use  of  the  fol- 
lowing :  Barium  sulphate  (heavy  spar,  fixed  white),  barium  col- 
ors free  from  barium  carbonate,  chrome  green,  copper,  zinc,  tin 
and  their  alloys  when  applied  as  metallic  colors,  cinnabar,  tin 
oxide,  tin  sulphide  in  the  form  of  mosaic  gold,  all  vitrified 
colors  in  glass,  glazes,  or  enamels,  and  colors  on  the  outside  of 
water-tight  vessels. 

3.  In  the  preparation  of  cosmetics  (materials    intended    for 

35 


36  THE   COAL-TAR   COLORS. 

the  cleaning,  care,  or  tinting  of  the  skin,  hair,  or  cavity  of  the 
mouth)  put  up  for  sale,  the  materials  enumerated  in  §  i  must 
not  be  used.  This  rule  does  not  apply  to  the  use  of  barium  sul- 
phate (heavy  spar,  fixed  white),  cadmium  sulphide,  chromium 
oxide,  cinnabar,  zinc  white,  tin  oxide,  tin  sulphide,  nor  to  cop- 
per, tin,  zinc,  and  their  alloys  in  powdered  form. 

4.  In  the  manufacture  of  toys  (including  picture-cards,  pic- 
ture-books, and  water-colors,  flower-pot  covers,  and  artificial 
Christmas  trees),  the  materials  forbidden  in  §  i  are  not  to 
be  used.  This  regulation  does  not  apply  to  the  articles  ex- 
cepted in  §  2,  nor  to  antimony  sulphide  and  cadmium  sulphide 
applied  as  color  in  gum  ;  lead  oxide,  in  varnish  ;  white  lead  as  a 
component  of  the  so-called  molded  wax,  if  the  same  does  not 
amount  to  more  than  one  part  in  one  hundred ;  lead  chromate 
by  itself  or  in  association  with  lead  sulphate,  in  oil  or  lacquer, 
covered  by  lacquer  or  varnish  ;  zinc  colors  insoluble  in  water,  in 
rubber  toys,  if  used  in  the  coloring  of  the  rubber,  or  as  lacquer 
or  oil  color,  applied  with  lac  or  varnish,  and  all  vitrified  t:olor 
applied  with  enamel.  The  provisions  of  §  §  7  and  8  are  strictly 
applicable  to  the  objects  therein  mentioned,  when  these  enter 
into  the  composition  of  the  toys. 

5.  In  book  printing  and  lithographing  in  connection  with  the 
manufactures  enumerated  in  §  §  2,  3  and  4,  only  colors  contain- 
ing arsenicum  are  forbidden. 

6.  Water  colors  of  all  kinds  are  not  to  be  sold  nor  offered  for 
sale  as  non-poisonous  unless  they  are  in  accordance  with  the 
requirements  of  §  4. 

7.  Arsenical  colors  shall  not  be  employed  in  the  manufacture  of 
tapestries,  upholstery,  carpets,  curtains,  wearing  apparel,  masks, 
candles  and  artificial  flowers  and  fruits.  This  regulation  does 
not  apply  to  the  use  of  arsenical  mordants  for  the  dyeing  and 
printing  of  textiles,  but  fabrics  so  prepared  shall  not  be  employed 
in  the  manufacture  of  the  articles  enumerated  in  the  preceding 
paragraph,  if  the  arsenical  compound  is  soluble  in  water,  or  pre- 
sent in  amount  greater  than  2  milligrams  to  100  square  cent,  of 
the  finished  fabric.     The  Chancellor  of  the  Empire  is  authorized 


LEGAL    ENACTMENTS.  37 

to  formulate  in  detail  the  method  for  estimating  the  amount  of 
arsenicum. 

8.  The  provisions  of  §  7  apply  to  the  manufacture  of  writing 
materials,  lamp  shades  and  lamp  decorations. 

The  manufacture  of  sacred  wafers  is  subject  to  the  conditions 
specified  in  §  i,  but  as  regards  those  not  intended  to  be  eaten, 
the  use  of  barium  sulphate  (heavy  spar,  fixed  white),  chrome  green 
and  cinnabar  is  allowed. 

9.  Water  colors,  or  gelatin  colors  containing  arsenicum,  are 
not  to  be  used  in  the  preparation  of  paints  for  floors,  ceilings, 
walls,  doors  or  windows  of  living  or  work-rooms,  nor  for  shades, 
shutters,  curtains,  furniture,  or  other  household  articles. 

10.  The  regulations  given  in  §  i,  do  not  apply  to  the  in- 
gredients there  enumerated,  if  such  are  merely  present  as  impuri- 
ties unavoidable  in  the  ordinary  manufacture,  and  not  essential 
constituents. 

ti.   These  regulations  do  not  apply  to  the  coloring  of  furs. 

12.  Whoever  prepares,  keeps  or  puts  up  food,  drink  or 
household  articles  in  violation  of  the  provisions  of  §  i  to  5,  7,  8, 
and  9,  or  sells  or  offers  for  sale  articles  prepared,  kept  or  put  up 
in  violation  of  said  provisions,  or  violates  the  requirements  of  §  6 
or  those  of  §  9,  or  sells  or  offers  for  sale  articles  made  in  violation 
of  the  provisions  of  §  9,  may  be  punished  by  a  fine  not  exceeding 
one  hundred  and  fifty  marks,  or  by  imprisonment. 

13.  In  addition  to  the  penalties  fixed  by  §  12,  articles  made, 
sold  or  exposed  for  sale  in  contravention  of  the  provisions  of  this 
Act  may  be  confiscated,  whether  the  property  of  the  accused  per- 
son or  not.  If  the  prosecution  or  conviction  of  any  particular 
person  is  impossible,  the  judgment  may  be  limited  to  the  con- 
fiscation. 

14.  The  provisions  of  the  law  of  May  14,  1879,  relating  to 
sale  of  food,  drink,  and  household  articles  (Reichs-Gesetzbl.,  p. 
146)  remain  undisturbed.  The  regulations  given  in  §  §  16  and  17 
of  that  law,  relating  to  violations  of  it,  apply  to  the  present  enact- 
ment. 

15.  This  law   takes  effect  on  May  i,   1888,  at  which    date 


38  THE    COAL-TAR    COLORS. 

the  imperial  decree  relating  to  the   employment  of  poisonous 
colors,  dated  May  i,  1882,  (Reichs-Gesetzbl.,  p.  55),  expires. 

Given  under  our  royal  hand  and  imperial  seal,  Ems,  July  5, 
1887.  William. 

von  boetticher. 

II.  The  Sonneberg  Chamber  of  Commerce  and  Trade  an- 
nounced in  a  bulletin  of  information,  on  December  4,  1887,  an 
opinion  as  to  the  points  in  the  law  of  July  5,  1887,  touching  the 
use  of  unwholesome  colors  in  the  manufacture  of  toys,  and  enum- 
erated the  following  colors,  which  under  that  law  may  be  em- 
ployed unrestrictedly :  All  blue  and  violet  aniline  (that  is,  coal- 
tar)  colors,  all  ponceaus,  all  orange  colors,  methyl  green,  brilliant 
green,  malachite  green,  chrysoidin,  naphthol  yellow,  Martius' 
yellow,  eosin,  phloxin,  safranin,  erythrosin,  fuchsin,  phenylene 
brown,  and  aniline  black.* 

III.  Announcement  concerning  the  examination  of  colors 
and  fabrics  for  arsenic  and  tin.     April  10,  1888. 

By  virtue  of  the  provisions  of  §  §  i  and  7,  of  the  law  relating 
to  the  use  of  injurious  colors  in  the  preparation  of  food,  drink, 
or  household  articles,  approved  July  5,  1887  (Reichs-Gesetzbl., 
p.  277),  I  order  that  the  following  methods  are  to  be  pursued  in 
the  recognition  of  arsenicum  and  tin  in  the  colors  employed 
in  food  or  drink  and  in  the  determination  of  the  amount  of 
arsenicum  in  fabrics  containing  arsenical  mordants. 

For  the  Chancellor  of  the  Empire, 

Berlin,  April  10,  1888.  von  Boetticher. 

Appendix. 

Directions  for  the  examination  of  colors  and  fabrics  for 
arsenicum  and  tin  (§  §  i  and  7,  of  the  law  relating  to  the  use 
of  injurious  colors  in  the  manufacture  of  food,  drink,  and  house- 
hold articles,  dated  July  5,  1887.). 

*  See  publications  of  the  Imper.  Health  Office,  p.  132,  No.  8. 


LEGAL   ENACTMENTS.  39 

A.  Methods  for  detecting  arsenicum  and  tin  in  artificially  colored 
articles  of  food  and  drink. 

/.  Solids. — With  solids  which  are  colored  through  the  entire 
mass,  20  grams  are  to  be  taken.  If  colored  superficially,  sufficient 
of  the  exterior  is  to  be  scraped  off  to  be  equivalent  to  20  grams 
of  the  material.  Smaller  amounts  of  material  are  to  be  used 
only  when  the  full  quantity  is  not  obtainable.  The  test-piece  is 
to  be  reduced  to  powder  in  any  suitable  manner  and  placed  in  a 
Berlin  porcelain  dish  with  a  convenient  quantity  of  hydrochloric 
acid  of  sp.  gr.  i.ioo  to  1.120  and  a  quantity  of  water  equal  to 
three  times  the  quantity  of  acid  added.  In  general,  25  c.  c.  of 
acid  and  75  c.  c.  of  water  will  be  sufficient;  0.5  gram  of  potas- 
sium chlorate  are  then  added,  the  dish  heated  on  the  water-bath, 
and,  when  the  fluid  reaches  the  temperature  of  the  bath,  small 
quantities  of  potassium  chlorate  are  added  from  time  to  time  until 
the  liquid  acquires  a  uniform  light  yellow  tint  and  becomes  clear. 
Two  grams  of  potassium  chlorate  will  usually  suffice  for  the 
operation.  Water  lost  by  evaporation  is  to  be  replaced.  When 
the  proper  condition  has  been  reached,  about  0.5  gram  more  of 
the  chlorate  are  added  and  the  dish  taken  from  the  bath,  cooled, 
filtered  into  a  400  c.  c.  flask,  and  the  filtrate  heated  on  the  water- 
bath  until  all  odor  of  chlorine  has  disappeared.  The  filter, 
together  with  any  precipitate,  is  washed  with  hot  water,  the 
washings  evaporated  to  50  c.  c,  and  the  liquid,  with  any  pre- 
cipitate that  may  be  in  it,  added  to  the  original  filtrate.  The 
total  volume  of  the  liquid  at  this  point  must  be  at  least  six  times 
that  of  the  hydrochloric  acid  taken.  Thus,  supposing  that  25 
c.  c.  of  hydrochloric  acid  have  been  used,  the  volume  must  not 
be  less  than  150  c.  c,  preferably  200  to  250  c.  c.  The  liquid 
is  then  maintained  for  three  hours  at  from  60°  to  80°  C,  while  a 
slow  current  of  pure  well-washed  hydrogen  sulphide  is  passed 
through;  the  heat  is  then  withdrawn,  the  gas  being  continued  until 
the  liquid  is  cold.  It  is  transferred  to  a  flask,  the  mouth  of 
which  is  covered  with  apiece  of  filter  paper,  and  allowed  to  stand 
for  twelve  hours  in  a  moderately  warm  place.     If  a  precipitate 


40  THE   COAL-TAR   COLORS. 

be  formed,  it  is  to  be  collected  upon  a  filter,  washed  with  hydro- 
gen sulphide  solution,  and  then,  while  still  moist,  treated  with 
yellow  ammonium  sulphide  which  has  been  somewhat  diluted 
with  weak  ammonium  hydroxide.  In  general  4  c.  c.  of  am- 
monium sulphide,  2  c.  c.  of  ammonium  hydroxide  of  sp.  gr. 
0.96,  and  15  c.  c.  of  water  will  be  satisfactory.  The  residue 
on  the  filter,  not  dissolved  by  this  mixture,  is  washed  with  water 
containing  a  little  ammonium  sulphide  and  the  filtrate  and  wash- 
ings evaporated  to  dryness  at  a  gentle  heat  in  a  porcelain  dish, 
not  over  six  cm.  in  diameter.  The  residue  treated  with  three 
c.  c.  of  red  fuming  nitric  acid,  the  dish  being  covered  by  a 
watch  glass,  and  the  acid  evaporated  at  a  gentle  heat.  If  the 
residue  is  still  dark,  the  treatment  with  nitric  acid  must  be  re- 
peated until  a  mass  appearing  yellow  when  moist,  is  obtained. 
This  is  mixed,  while  still  moist,  with  finely  powdered  sodium 
carbonate,  until  strongly  alkaline,  a  mixture  of  one  part  of 
sodium  nitrate  and  three  parts  of  sodium  carbonate  added,  and 
sufficient  water  to  make  a  pasty  mass,  which  is  then  thorcjughly 
mixed.  The  mass  is  heated  in  a  crucible  to  sintering  or  incipi- 
ent melting ;  a  high  heat  is  to  be  avoided.  A  colorless  or  white 
residue  should  be  obtained.  If  the  mass  is  colored,  it  should  be 
re-heated  with  a  little  sodium  nitrate,  until  the  colorless  condi- 
tion is  reached.* 

The  melt  is  dissolved  in  warm  water  and  filtered  through  a 
wet  filter.  If  tin  be  present,  it  will  be  found  on  the  filter,  in  the 
form  of  stannic  oxide,  while  all  the  arsenicum  will  be  in  the 
filtrate  in  the  form  of  sodium  orthoarsenate.  If  there  be  a  resi- 
due on  the  filter,  it  must  be  borne  in  mind  that  minute  amounts 
of  tin  may  pass  into  the  filtrate.  The  residue  is  washed  with 
cold  water,  then  three  times  with  a  mixture  of  equal  parts  of 
alcohol  and  water,  the  washings  evaporated  so  that  the  total  vol- 
ume including  the  filtrate  does  not  exceed  10  c.  c,  and  nitric 
acid  added,  drop  by  drop,  until  the  liquid  is  acid.    If  a  precipitate 

*  If  the  melt  persistently  remains  black  it  contains  copper,  owing  to  the 
slight  solubility  of  copper  sulphide  in  ammonium  sulphide. 


LEGAL    ENACTMENTS.  4I 

of  Stannic  hydroxide  appear  it  is  filtered  off  and  washed  as  de- 
scribed above.  The  further  procedure  for  the  detection  of  tin  is 
given  below. 

For  the  recognition  of  the  arsenicum,  it  is  converted  into 
ammonium  arsenmolybdate.  For  this  purpose,  the  liquid, 
rendered  acid  by  nitric  acid,  as  described  above,  is  freed  from 
carbonic  and  nitrous  acids  by  warming,  cooled,  the  clear 
(filtered,  if  necessary)  solution,  which  should  be  about  15  c.  c, 
mixed  in  a  flask  with  about  an  equal  volume  of  ammonium 
molybdate  solution,*  and  allowed  to  stand  without  warmmg  for 
three  hours.  If  through  incomplete  washing  of  the  hydrogen 
sulphide  precipitate,  any  phosphate  has  been  retained,  a  yellow 
precipitate  of  ammonium  phosphomolybdate  will  separate;  other- 
wise, the  liquid  will  remain  clear.  The  clear  (if  necessary, 
filtered)  liquid  is  heated  on  the  water  bath  for  five  minutes,  at  the 
boiling  point.*  If  arsenicum  be  present,  a  yellow  precipitate  of 
ammonium  arsenmolybdate,  together  with  molybdic  anhydride 
will  separate. f 
.  After  standing  for  one  hour,  the  liquid  is  decanted 
through  a  filter,  the  precipitate  washed  twice  with  a  mixture 
of  100  parts  of  the  molybdate  solution,  20  parts  nitric  acid 
of  sp.  gr.  1.200  and  80  parts  of  water,  and  dissolved, 
by  the  aid  of  heat,  in  from  two  to  four  c.  c.  of  ammon- 
ium hydroxide  sp.  gr.  0.96,  four  c.  c.  of  water,  filtered,  if 
necessary,  mixed  with  one-fourth  its  volume  of  alcohol,  and 
then  with  two  drops  of  the  solution  of  ammonium  chloride  and 
magnesium  chloride.  The  arsenicum  separates  on  standing,  as 
ammonium  magnesium  arsenate,  more  or  less  crystalline  in  form, 
which  is  to  be  collected  on  a  filter  and  washed  with  as  small  as 

*  Dissolve  one  part  of  molybdic  anhydride  in  four  parts  of  ammonium 
hydroxide  (sp.  gr.  0.96),  and  pour  the  solution  into  15  parts  of  nitric  acid  (sp. 
gr.  1.200);  allow  the  liquid  to  stand  in  a  moderately  warm  place  for  several 
days  and  decant  the  clear  portion  for  use. 

f  It  is  best  to  continue  the  heating  until  the  molybdic  anhydride  begins  to 
separate. 

4 


42  THE   COAL-TAR   COLORS. 

possible  a  quantity  of  a  mixture  of  one  part  of  ammonium 
hydroxide,  two  parts  of  water,  and  one  part  of  alcohol.  The 
precipitate  is  to  be  dissolved  in  the  smallest  possible  quantity  of 
dilute  nitric  acid,  the  solution  evaporated  to  small  bulk,  one 
drop  of  it  placed  in  a  porcelain  basin  and  another  on  a  glass 
slide.  To  the  first  drop,  a  solution  of  silver  nitrate  is  added, 
then  a  drop  of  ammonium  hydroxide  sp.  gr.  .096  is  applied  to 
the  edge  of  the  mixture.  If  arsenicum  be  present,  a  red-brown 
streak  will  appear.  The  drop  on  the  object  glass  is  made 
akaline  with  the  smallest  possible  quantity  of  ammonium 
hydroxide,  by  which  there  appears  very  soon,  if  arsenicum  be 
present,  a  crystalline  precipitate  of  ammonium  magnesium 
arsenate. 

For  the  detection  of  tin,  the  filter  or  filters  containing  the 
stannic  oxide  are  to  be  dried,  burned  in  a  porcelain  crucible,  and 
weighed.*  Further  examination  for  tin  will  be  necessary  only 
when  the  residue,  after  deducting  the  filter  ash,  weighs  more 
than  .002  gram.  In  this  case,  the  residue  is  to  be  placed"  in  a 
porcelain  boat  which  is  inserted  in  a  tube  of  hard  glass,  one  end 
of  which  has  been  drawn  out  to  a  fine  jet.  A  stream  of  pure  dry 
hydrogen  is  passed  through  the  tube,  the  temperature  being 
slowly  raised  and  continued  until  no  vapor  of  water  escapes,  that 
is,  until  all  the  oxide  is  reduced.  The  boat  is  allowed  to  cool 
in  the  stream  of  gas,  removed,  tilted  slightly,  a  few  drops  of 
hydrochloric  acid  sp.  gr.  i.io  to  1.12,  placed  in  the  lower  end, 
again  placed  in  the  tube  and  subjected  to  a  slow  current  of  the 
hydrogen  gas.  The  boat  is  inclined  so  that  the  hydrochloric 
acid  comes  in  contact  with  the  reduced  tin,  and  is  then  slightly 
heated.  The  tin  dissolves,  forming  stannous  chloride,  with  libera- 
tion of  hydrogen.  The  boat  is  allowed  to  cool  in  the  current  of 
gas,  removed,  if  necessary,  treated  with  a  few  drops  of  a  mixture 

*  If  the  residue  is  black,  in  consequence  of  the  presence  of  copper  oxide,  it 
is  to  be  warmed  with  nitric  acid  and  evaporated  in  the  water-bath  to  dryness, 
and  a  few  drops  of  nitric  acid  with  a  little  water  added,  the  residue  collected 
on  a  filter,  washed,  dried,  ignited  and  weighed. 


LEGAL   ENACTMENTS.  43 

of  three  parts  of  water  and  one  part  of  hydrochloric  acid,  and 
different  drops  of  the  solution  tested  for  tin,  by  mercuric  chlor- 
ide, gold  chloride  and  hydrogen  sulphide,  the  latter  test  being 
tried  both  before  and  after  the  addition  of  bromine  or  chlorine 
water. 

A  black  residue,  insoluble  in  the  acid,  remaining  after  the 
treatment  of  the  contents  of  the  boat  with  hydrochloric  acid, 
may  be  antimony. 

//.  Liquids,  Fruii  Jellies,  and  Similar  Substances. — In  such 
cases,  a  quantity  of  the  material  is  to  be  weighed  out  that  shall 
be  equivalent  to  20  grams  of  the  dried  substance.  For  raspberry 
syrup,  30  grams  must  be  taken  ;  for  currant  jelly  35  grams,  and 
for  red  wine,  vinegar  and  such  fluids,  from  800  to  1000  grams 
must  be  used.  Smaller  quantities  may  be  used  only  when  the 
full  amount  is  not  obtainable. 

Fruit  juices,  jellies  and  such  substances  are  treated  exactly  as 
directed  above,  with  hydrochloric  acid,  potassium  chlorate,  etc.; 
dilute,  non-acid  liquids  are  concentrated  by  evaporation,  to  a 
small  volume,  and  treated  as  before ;  acid  liquids  are  distilled  to 
a  small  volume,  the  distillate  is  mixed  with  hydrochloric  acid 
and  saturated  with  hydrogen  sulphide,  any  precipitate  so  ob- 
tained being  added  to  that  obtained  from  the  liquid  in  the  retort 
similarly  treated. 

B.  Procedure  for  the  detection  of  arsenicum  in  yarn  and  fab- 
rics (§  7  of  the  law).* 


*  It  is  allowable  for  the  investigator  to  make  a  preliminary  test  by  Marsh's 
method,  using  a  sufficiently  large  quantity  of  the  material,  and  thus  determine 
the  presence  or  absence  of  arsenicum.  Should  the  result  be  negative  further 
procedure  is  unnecessary.  [In  this  and  similar  cases,  Reinsch's  test,  which  is 
much  more  convenient  than  Marsh's,  will  be  found  sufficient  for  preliminary 
examination.  It  is  advisable  to  use  a  rather  large  amount  of  hydrochloric 
acid,  otherwise  arsenates  may  be  overlooked.  The  processes  given  in  the 
text  for  the  destruction  of  the  organic  matter  are  now  not  much  employed,  since 
the  methods  involving  the  use  of  sulphuric  acid  with  or  without  nitric,  are  more 
rapid  and  satisfactory.  These  methods  will  be  found  described  in  Fresenius' 
Quantitative  Analysis  and  other  works  of  similar  scope.     Translator.] 


44  THE    COAL-TAR   COLORS. 

Thirty  grams  of  the  material  to  be  tested  are  cut  fine  and 
soaked  in  water  at  from  70  to  80°  C.  for  from  three  to  four  hours. 
The  liquid  is  filtered,  any  residue  is  washed,  and  the  filtrate  and 
washings  are  concentrated  to  about  25  c.c,  cooled,  mixed  with 
5  c.c.  of  pure  sulphuric  acid,  and  tested  by  Marsh's  test,  with 
due  precautions.  If  an  arsenical  mirror  is  obtained  it  shows 
that  arsenicum  is  present  in  the  fabric,  in  a  form  soluble  in 
water. 

If  the  result  by  the  above  test  is  negative,  a  further  quantity  of 
10  grams  is  taken  and  the  superficial  area  determined.  In 
the  case  of  yarn  the  area  is  to  be  determined  by  comparison  with 
a  fabric  woven  from  yarn  of  similar  size.  If  the  quantities 
necessary  for  the  examinations  are  not  to  be  obtained,  smaller 
quantities  may  be  used,  and  this  part  of  the  test  may,  in  such 
case,  be  carried  out  upon  a  portion  of  that  which  has  been 
treated  with  water  and  afterwards  dried. 

The  yarn  or  fabric  is  to  be  cut  fine,  introduced  into  a  hard 
glass  retort  of  400  c.c.  capacity,  and  covered  with  100  c.c.  of 
hydrochloric  acid  sp.  gr.  1.19.  The  neck  of  the  retort  is  drawn 
out  and  bent  at  an  obtuse  angle,  and  the  retort  mounted  so  that 
the  first  portion  of  the  neck  points  obliquely  upward  and  the 
second  portion  sharply  downward.  The  end  of  the  neck  is 
attached  to  a  Liebig's  condenser  and  the  joint  made  tight  with 
a  caoutchouc  tube.  The  condenser  is  attached  by  an  air-tight 
joint  to  a  receiver  of  500  c.c.  capacity,  in  which  has  been  placed 
200  c.c.  of  water,  and  which  is  immersed  in  a  dish  of  cold 
water.  The  outlet  tube  of  the  receiver  is  connected  in  a  suit- 
able manner  with  a  Peligot's  tube. 

About  an  hour  after  the  addition  of  the  hydrochloric  acid,  5 
c.c.  of  cold  saturated  solution  of  non-arsenical  ferric  chloride  is 
introduced  into  the  retort  and  heat  applied.  When  the  excess 
of  hydrochloric  acid  has  passed  over  the  heat  is  raised  until  the 
liquid  boils,  and  continued  until  the  contents  of  the  retort  begin 
to  foam.  The  liquid  is  allowed  to  cool,  50  c.c.  of  hydrochloric 
acid  of  sp.  gr.  1,19  added,  and  the  distillation  resumed.  The 
contents  of  the  receiver,  colored  by  organic  matter,  are  mixed 


LEGAL   ENACTMENTS.  45 

with  the  liquid  that  has  collected  in  the  Peligot  tube,  diluted 
with  distilled  water  to  about  600  c.c,  and  treated,  first  warm, 
and  then  in  the  cold,  with  pure  washed  hydrogen  sulphide.  At 
the  end  of  twelve  hours  the  brown  precipitate,  consisting  in 
whole  or  in  part  of  organic  matter,  is  collected  on  an  asbestos  filter, 
which  rests  in  a  funnel  provided  with  a  stopcock,  and  washed 
briefly.  The  cock  is  closed  and  the  mass  treated  with  a  few  c.c. 
of  a  solution  of  bromine  in  hydrochloric  acid  of  sp.  gr.  1.19, 
a  watch  glass  being  placed  over  the  top  of  the  funnel  to  avoid 
loss.  After  action  for  half  an  hour  the  liquid  is  allowed  to  run 
from  the  funnel  into  the  flask  in  which  the  precipitate  was  orig- 
inally formed,  on  the  sides  of  which  some  of  the  material 
remains.  The  residue  on  the  filter  is  to  be  washed  with  hydro- 
chloric acid  of  the  usual  strength.  The  filtrate  and  washings 
are  to  be  mixed  with  excess  of  ferric  chloride,  the  mixture 
introduced  into  a  distillation  apparatus  of  smaller  size,  but  con- 
structed as  before  detailed,  the  flask  containing  the  solution  be- 
ing rinsed  with  hydrochloric  acid  of  the  usual  strength,  the 
rinsing  being  added  to  the  contents  of  the  retort.  The  distilla- 
tion is  conducted  exactly  as  before  described.  The  distillate  is 
usually  clear  and  colorless.  It  is  diluted  to  about  700  c.c,  pre- 
cipitated with  hydrogen  sulphide,  as  before  directed,  and  after 
twelve  hours  standing  the  precipitated  arsenious  sulphide  is  col- 
lected on  a  filter  (which  has  been  successively  washed  with  dilute 
hydrochloric  acid,  water  and  alcohol,  dried  at  110°  C,  and 
weighed),  washed  with  water,  absolute  alcohol,  warm  hydrogen 
sulphide  solution,  absolute  alcohol  again,  dried  at  110°  C,  and 
weighed.  The  quantity  of  arsenicum  is  calculated,  and  from 
the  data  obtained  in  the  original  measurement  the  proportion 
of  arsenicum  in  100  sq.  cm.  of  material  may  be  ascertained. 

England. 

In  the  Sale  of  Food  and  Drugs  Act  of  1875,  paragraph  3, 
to  which  Mr.  Otto  Hehner,  of  London,  has  kindly  referred  me, 
is  found  to  be  to  our  purpose. 

**  3.  No  person  shall  mix,  color,  stain,  or  powder,  or  order  or 


46  THE   COAL-TAR   COLORS. 

permit  any  other  person  to  mix,  color,  stain,  or  powder,  any  article 
of  food  with  any  ingredient  or  material  so  as  to  render  the  article 
injurious  to  health,  with  intent  that  the  same  may  be  sold  in  that 
state,  and  no  person  shall  sell  any  such  article  so  mixed,  colored, 
stained,  or  powdered,  under  a  penalty  in  each  case  not  exceeding 
fifty  pounds  for  the  first  offence;  every  offence  after  a  conviction 
for  a  first  offence  shall  be  a  misdemeanor  for  which  the  person, 
on  conviction,  shall  be  imprisoned  for  a  period  not  exceeding 
six  months  at  hard  labor." 

France. 

(This  abstract  is  given  by  Dr.  Weyl  in  the  original  French.) 

LIST  OF  HARMFUL  AND  HARMLESS  COLORS. 

L  SUBSTANCES  THAT  MAY  BE  USED. 

Mineral    Colors. 
WJiite, — Chalk.     Precipitated  barium  sulphate  (to  be  used  in 
small  amount.) 

Blue. — Prussian  or  Berlin  blue,  ultramarine. 
Violet.  — Violet  ultramarine. 
Brown. — Ochre,  manganese  brown. 
Green. — Green  ultramarine. 
Yellow. — Yellow  ochre. 

Organic  Colors. 

White. — Farina  flour,  starch. 

Red. — Cochineal  carmine,  carthamic  acid  (from  saffron),  red- 
wood, artificial  alizarin  and  purpurin,  cherry  and  beet  juices, 
lakes  prepared  with  these  substances. 

Orange. — Annatto ;  mixtures  of  harmless  red  and  yellow 
colors. 

Yellow. — Saffron,  safiflower,  turmeric,  quercitron,  extract  of 
yellow  wood,  French  berries;  aluminous  lakes  prepared  with 
these  colors. 

Green. — Spinach  green,  Chinese  green  ;  mixtures  of  harmless 
blue  and  yellow  colors. 

Violet. — Archil,  India  wood ;  mixtures  of  harmless  blue  and 
red  colors. 


LEGAL    ENACTMENTS.  47 

Blue. — Indigo,  litmus,  Archil  blue. 

Brown. — Caramel,  liquorice,  extract  of  chestnut  wood,  ex- 
tract of  catechu. 

n.  SUBSTANCES  NOT  TO  BE  EMPLOYED. 

Mineral   Colors. 

Coftfaining  Copper. — Mountain  blue. 

Containifig  Lead. — Massicot  red  lead,  orange  mineral,  Paris 
yellow,  Cassel's  yellow.  Turner's  yellow,  white  lead,  silver 
white,  Naples  yellow,  chrome  yellow,  orange  chrome. 

Containing  Barium. — Barium  chromate,  yellow  ultramarine. 

Containing  Arsenicum. — Copper  arsenite,  Scheele's  green, 
Schweinfurth    green,    mixed     green,    also    mercuric    sulphide 

(vermilion). 

Organic   Colors. 
Gamboge,  aconite,  fuchsin,  and  derivatives,  e.g.,  Lyons  blue, 
eosin.     Colors  containing  nitro-groups,  e.  g.,  naphthol  yellow, 
Victoria  yellow.     Colors  prepared  from  diazo-compounds,  e.  g., 
tropseolins  and  xylidine  red. 

Italy. 

[An  abstract  of  these  regulations  is  given  by  Dr.  Weyl  in  the 
original  Italian.  They  provide  that  the  sale,  keeping  for  sale, 
or  dealing  in  any  article  of  food  or  drink  which  is  known  to  be 
spoiled,  diseased,  adulterated,  or  otherwise  injurious  to  health, 
and  contrary  to  the  regulations,  may  be  punished  by  fine  or  im- 
prisonment, maximum  and  minimum  penalties  and  terms  being 
enumerated. 

The  manufacture  and  sale  of  vessels,  etc.,  intended  to  contain 
articles  of  food  and  drink,  which  vessels,  etc.,  contain  or  are 
coated  with  any  metal  or  varnish  or  other  covering,  which  may 
be  likely  to  make  the  food  injurious,  are  forbidden. 

The  Superior  Council  of  Health,  with  the  approval  of  the 
Minister  of  the  Interior,  is  authorized  to  issue  a  list  of  colors  con- 
sidered injurious,  and  which  are  not  to  be  used  in  the  preparation 
of  food,  drink,  toys,  household  articles,  etc.  Heavy  fines 
are  imposed  in  case  of  the  use  of  the  substances  so  prohibited.] 


48  THE    COAL-TAR   COLORS. 

Abstract  from  regulations  of  the  administration  of  the  municipal- 
ity of  Milan,  {not yet p?'oclai?ned). 

A.  It  is  forbidden  to  add  coloring  matters  of  any  kind  to  the 
naturally  colored  articles  of  food  and  drink,  such  as  wine,  wine- 
vinegar,  fruit  juices,  preserved  fruits,  preserved  vegetables,  such 
as  saffron,  etc. 

Paper,  tissue,  etc.,  used  for  wrapping  articles  of  food,  must  not 
be  colored  with  poisonous  colors,  and  the  colors  denominated  as 
poisonous  in  the  law  of  the  German  Empire  of  July  5th,  1887, 
are  hereby  designated  as  poisonous. 

For  the  coloring  of  articles  of  food  and  drink  not  naturally 
colored,  and  of  which  the  practice  of  artificial  coloring  is  well 
known,  for  instance,  liquors  and  confections,  the  employment 
of  the  poisonous  colors  referred  to  above,  as  well  as  all  coal-tar 
colors  not  cited  below,  is  until  further  notice  forbidden :  certain 
azo-colors  and  purpurin  are  permitted.  Inasmuch  as  several  of 
the  colors  here  designated  occur  in  commerce  under  various 
names,  any  one  who  intends  to  employ  such  color  will  be  obtiged 
to  ascertain  whether  it  belongs  to  the  permitted  class. 

AUSTRIO-HUNGARY. 

In  the  official  announcement  of  March  4,  1824,  Z.  11379, 
the  harmful  colors  which  are  not  allowed  to  be  used  for  painting 
toys,  or  for  candies,  and  the  harmless  ones  which  are  permitted 
for  these  purposes,  are  enumerated  as  follows:  — 

A.  NOT  ALLOWED  FOR  PAINTING  TOYS. 

White  lead,  zinc  white. 

Orpiment,  king's  yellow,  Naples  yellow,  massicot,  English 
yellow,  mineral  yellow,  chrome  yellow,  and  gamboge. 

Verdigris,  Braunschweig  green,  mountain  green,  Bremen 
green,  Swedish  or  Scheele's  green,  mitis  green,  Vienna  green, 
Schvveinfurth  green. 

Mountain  blue,  mineral  blue,  smaltz,  Berlin  blue,  when  con- 
taining copper. 

Vermilion,  red  lead. 


LEGAL   ENACTMENTS.  49 

•    •  HARMLESS  AND  THEREFORE  PERMITTED. 

Chalk,  gypsum,  white  bone  ash,  ivory  white,  hartshorn  ash. 

Dutch  pink,  turmeric,  yellow  ochre,  orlean  (an  infusion  of 
yellow  wood  mixed  with  one-fourth  of  alum  and  gum.) 

Sap  green,  all  greens  made  from  harmless  yellow  and  blue 
colors,  Veronese  green. 

Pure  Berlin  blue,  new  blue,  indigo  solution  with  starch,  Saxon 
blue,  solution  of  indigo  in  sulphuric  acid,  litmus,  sap  blue,  and 
cornflower  blue. 

Carmine,  lac,  stick-seed,  madder,  and  Florentine  lac,  Ar- 
menian bolus,  pure  ferric  oxide,  Pernambuco  and  Brazil  wood 
infusion,  mixed  with  alum  and  gum. 

B.  For  candies  the  following  colors  are  regarded  as  harmful : 
cinnabar  and  red  lead,  yellow,  blue  and  green,  colors  above 
designated  as  harmful,  with  mixtures  of  such  yellow  and  red 
colors  and  such  red  and  blue  colors,  imitation  gold  and  silver 
leaf.  As  harmless,  the  following :  juice  of  red  berries,  kermes, 
bearberry,  red-beet  juice,  onion  peelings,  infusions  of  cochineal 
with  cream  of  tartar,  of  red  poppies,  of  bluebottle  (Centaurea 
cyanus,  L.),  saffron,  safflower,  turmeric,  infusion  of  "marigold 
flowers,  expressed  juice  of  blue  flowers,  such  as  bluebottles  and 
violets,  litmus,  spinach  juice,  mixtures  of  harmless  yellow  and 
blue  colors.  Pomegranate  yellow,  decoction  of  oleander  with 
sodium  hydroxide,  cochineal  infusion  with  lime  water,  mixtures 
of  harmless  blue  and  red  colors,  genuine  gold  and  silver  leaf. 

11.  According  to  the  ministerial  announcement  of  September 
19,  1848,  Z.  3075,  of  a  governmental  order  of  October  5, 
1848,  Z.  53  169,  only  the  following  colors  are  to  be  used  for 
painting  edibles,  confections,  and  tragacanth  preparations,  as 
well  as  all  show  pieces  prepared  by  candy  makers  and  not  in- 
tended for  consumption. 

White.  — Tragacan  th. 

Red. — Cochineal,  carmine,  kermes,  infusion  of  red  poppy. 

Yellow. — Saffron,  safllower,  and  turmeric. 

Blue. — March  violet,  bluebottle,  indigo,  Prussian  blue, 
ultramarine,  sea  blue  (a  form  of  artificial  ultramarine). 


50  THE   COAL-TAR   COLORS. 

Green. — Spinach  juice,  mixtures  of  permissible  blue  and  yel- 
low colors. 

Violet, — Mixtures  of  harmless  blue  and  red  colors,  cochineal 
infusion  with  lime  water. 

Gold  Color. — Pure  gold  leaf. 

Silver  Color. — Pure  silver  leaf. 

All  other  colors,  no  matter  what  name  they  may  bear,  are 
forbidden  to  the  extent  that  even  to  keep  them  in  stock  in  the 
business  department  or  work  rooms  of  any  given  establishment, 
will  constitute  an  infringement  of  these  regulations  and  bring 
about  liability  to  the  penalties  provided. 

III.  In  accordance  with  the  orders  of  the  government  of  lower 
Austria  (January  23,  1859,  Z.  55507),  the  provisions  for  the 
employment  of  Alpine  red  (murexide)  as  a  color  were  designated 
as  follows:  ''This  color  can  only  be  made  permanent  by  the 
employment  of  mercuric  chloride.  In  its  preparation  the  work- 
men come  frequently  and  for  considerable  periods  in  contact 
with  the  mercuric  chloride,  and  by  neglect  of  the  proper  precau- 
tions, serious  results  must  occur.  To  prevent,  as  far  as  possible, 
the  injuries  that  must  follow  long  contact  with  materials  charged 
with  this  substance,  it  is  necessary  that  the  workmen  engaged  in 
using  murexide  avoid  handling  it  with  abraded  hands ;  that  they 
should  not  allow  the  mercuric  chloride  solution  to  remain  in 
contact  with  the  skin  longer  than  is  absolutely  necessary,  and  as 
often  as  such  contact  occurs  should  rinse  their  hands  with  clean 
water,  and  take  especial  care  to  wash  the  hands  prior  to  taking 
or  preparing  food.  This  information  is  given  in  order  that  those 
in  charge  of  such  establishments  shall  not  neglect  to  give  neces- 
sary instructions  to  workmen." 

IV.  Regulations  promulgated.  May  i,  1866,  by  the  Imperial 
Secretary  of  State  for  Austria,  relating  to  the  employment  of 
poisonous  colors  and  unwholesome  preparations  in  various  articles 
of  household  use,  and  to  the  sale  of  the  same.  (R.  G.  Bl. 
Royal  Austrian  Empire,  p.  137.)  Quoted  from  publications  of 
the  Imperial  Health  Office,  1887,  351,  No.  23.  The  employ- 
ment of  colors  containing  metals  (except  iron),  gamboge,  picric 


LEGAL    ENACTMENTS.  5 1 

acid,  or  aniline,  is  forbidden  for  all  articles  of  consumption,  food 
or  drink,  including  devices  and  figures  made  from  starch  and  sugar. 
Preparations  and  colors  containing  arsenicum,  antimony,  lead, 
cadmium,  copper,  cobalt,  nickel,  mercury  (with  the  exception  of 
pure  mercuric  sulphide),  zinc,  or  gamboge,  are  not  to  be  em- 
ployed for  coloring  or  decorating  children's  toys.  The  materials, 
the  employment  of  which  is  forbidden  in  the  above  paragraphs, 
or  conditionally  permitted,  are  not  to  be  used  on  earthenware 
employed  for  holding  food,  except  when  the  coloring  material  is 
burnt  in.  Artificial  flowers  colored  with  arsenicum  compounds, 
or  natural  flowers  of  which  any  part  may  have  been  tinted  by 
dipping  in  arsenical  solution,  are  only  allowed  when  the  falling 
off  of  any  of  the  material  is  completely  prevented  by  varnish. 
Tapestry  containing  arsenical  colors  will  only  be  allowed  when 
the  portions  so  colored  are  protected  by  a  varnish  coating.  The 
employment  of  arsenical  colors  for  the  painting  of  walls  of 
.  living  rooms,  or  other  places  where  persons  collect,  is  forbidden. 
The  employment  of  any  substance  which  in  any  form  or  manner 
in  which  it  is  used  endangers  health,  is  forbidden  in  the  prepa- 
ration of  articles  of  food,  table  and  culinary  ware,  clothing,  and 
all  kinds  of  toilet  articles.  In  addition  to  the  manufacture  of 
the  articles  which  do  not  accord  with  the  preceding  conditions, 
trading,  retailing,  or  other  dealing  in  them  is  forbidden. 
Violations  of  these  regulations  which  are  not  provided  for  by 
the  general  penal  code  are  punishable  by  the  provisions  of  the 
regular  ministerial  orders  of  September  30,  1881,  R.  G.  P.  L. 
198.  Signed,  Count  Belcredi,  m.  p. ;  Baron  von  Wiillerstorf, 
M.  P.  ;  Kt.  von  Komers,  m.  p. 

V.  In  reply  to  a  formal  question  as  to  what  course  is  to  be 
pursued  when  articles  of  food  have  been  found  to  be  colored 
with  aniline  red,  free  from  arsenicum,  and,  therefore,  not  injuri- 
ous to  health,  the  Royal  Imperial  Secretary  of  the  Interior,  by 
a  proclamation  of  November  21,  1881,  Z.  16033  (State  pro- 
clamation, December  19,  1881,  Z.  75960)  after  consultation 
with  the  chief  sanitary  authority  determined  not  to  amend 
the  regulations  of  May  i,  1866,  since,  although  it  is  a  fact  that 


52  THE   COAL-TAR   COLORS. 

fuchsin  free  from  arsenicumj  is  now  in  the  market,  no  evidence 
is  at  hand  that  a  preparation  of  poisonous  quality  is  not  in  com- 
merce under  the  same  name.  Further,  the  question  as  to  the 
poisonous  or  non-poisonous  character  of  the  aniline  colors  free 
from  metal  is  still  in  dispute,  and  observations  are  on  record  to 
the  effect  that  the  continued  consumption  of  liquids  colored  by 
fuchsin  free  from  arsenicum  has  resulted  in  material  disturb- 
ances of  health.  The  use  of  fuchsin  as  a  coloring  material  in 
all  kinds  of  food  is  all  the  less  to  be  permitted  since  coloring 
matters  are  not  wanting  which  suffice  for  the  purpose  and  are 
unsuspicious  from  a  sanitary  point  of  view. 

VI.  Regulations  of  the  Royal  Imperial  Austrian  Secretary  of 
the  Interior  concerning  the  employment  of  aniline  or  other 
coal-tar  colors  in  the  preparation  of  articles  of  food,  dated 
March  i,  1886,  R.  G.  P.  L.  (Reichsgesetzblatt  fiir  die  im  Reich- 
rathe  vertretenen  Konigreiche  und  Lander.  Quoted  from  the 
publications  of  the  Imperial  Health  Office,.  Germany,  1886,  . 
348).  The  employment  of  colors  produced  by  chemical 'treat- 
ment of  'the  aniline  or  other  coal-tar  derivatives,  including  roso- 
lic  acid  produced  by  various  methods,  in  the  preparation  of  all 
articles  of  food,  is  prohibited. 

In  accord  with  §§  i  and  6  of  regulations  of  May  i,  1866. 
Taaffe,  m.  p.,  Prezak,  m.  p.,  Pino,  m.  p. 

VII.  Supplement  relating  to  the  application  of  rosolic  acid  to 
the  coloring  of  articles  of  food,  added  by  the  Royal  Imperial 
Austrian  Secretary  of  the  Interior.  (Quoted  from  the  publica- 
tions of  the  Imperial  Health  Office,  1887,  351,  23.)  In  answer 
to  the  formal  question  as  to  the  permissibility  of  the  use  of 
rosolic  acid  for  coloring  articles  of  food,  the  following  is  issued 
with  the  consent  of  the  chief  sanitary  authority  :  ^'  In  view  of 
the  more  exact  information  acquired  as  to  the  composition  of 
the  compounds  obtained  from  rosaniline  by  chemical  action  and 
applicable  as  coloring  materials,  the  expression  in  §  i  of  the 
regulations  of  May  i,  1866,  '  the  employment  of  colors  which 
contain  aniline,'  etc.,  must  not  be  taken  in  the  sense  that  the 
said  colors  contain  aniline,  but  rather  the  expression  must  be 


SCOPE   OF   THE   INVESTIGATION.  53 

understood  to  mean  colors  produced  by  chemical  action  on 
aniline.  In  this  sense,  rosolic  acid  prepared  from  rosaniline 
must  be  regarded  as  a  derivative  of  the  latter,  and  hence,  as  an 
aniline  color,  is  subject  to  the  conditions  of  §  i  of  the  afore- 
mentioned regulations.  As  to  the  second  variety  of  rosolic  acid 
prepared  by  the  action  of  oxalic  acid  upon  carbolic  acid,  which 
differs  as  to  composition  and  properties  very  slightly  from  the 
acid  first  named,  §  i  of  the  aforementioned  regulations  does  not 
apply,  but  §  6  of  the  same  does  apply  all  the  more  positively, 
since,  apart  from  the  absence  of  trustworthy  knowledge  of  the 
action  of  pure  rosolic  acid  upon  the  human  organism,  it  comes 
into  commerce  contaminated  by  the  injurious  materials  employed 
in  its  manufacture,  and  therefore,  in  the  manner  and  form  in 
which  it  is  employed,  it  is  actually  liable  to  endanger  health. 
The  Secretary  of  the  Interior  takes  this  opportunity  to  advise 
that  recently  numerous  organic  substances,  especially  prepared 
from  coal-tar  and  applicable  as  colors,  have  been  prepared,  which 
on  the  one  hand,  on  account  of  their  unknown  action  and  un- 
known influence  on  the  human  organism,  on  the  other  hand 
from  their  contamination  with  substances  of  suspicious  influ- 
ence, must  not  be  employed  in  the  preparation  of  food  and 
drink,  and  therefore,  are  to  be  dealt  with  in  accordance  with 
provision  of  §  6  of  the  regulations  above  quoted." 

SCOPE  OF  THE  INVESTIGATION. 

The  review  of  the  existing  literature  shows  that  certainty  as 
to  the  unwholesomeness  or  toxic  nature  of  the  coal-tar  colors 
has  not  yet  been  attained,  and  cannot  be  attained  because  re- 
searches with  definite  purpose  are  almost  entirely  wanting.  On 
the  other  hand,  the  majority  of  civilized  nations  have  been  con- 
strained to  forbid,  by  rules  and  regulations,  the  employment  of 
certain  colors  in  the  preparation  of  food  or  household  articles. 

Since  my  labors  in  this  field  forced  me  to  the  conclusion  that 
a  rational  legislative  control  of  this  question  could  only  be  based 
upon  more  comprehensive  information  than  seemed  to  be  attain- 


54  THE   COAL-TAR   COLORS. 

able,  I  resolved  to  test  the  existing  statements  concerning  cer- 
tain coal-tar  colors,  and  further,  to  carry  out  investigations  on 
as  many  of  these  dyes  as  possible.  Thus,  following  research 
was  inaugurated,  and  as  already  stated  was  pursued  in  strictly 
practical  relations.  Frequently,  to  the  regret  of  the  experi- 
menter, interesting  lines  of  research  must  be  passed  by,  which 
would  lead  to  information  concerning  the  ultimate  products  re- 
sulting from  the  ingested  substances,  the  origin  of  the  toxic 
symptoms,  and  the  disturbances  of  metabolism  under  the  in- 
fluence of  the  foreign  materials.  The  abundance  of  new  observ- 
ations offered  added  an  additional  reason  for  leaving  these  side- 
issues  untouched,  at  least  in  the  preliminary  stage.  No  excuse 
should  be  needed  for  the  frequent  allusion  to  questions  of  theor}', 
since  the  data  herewith  presented  are  not  the  result  of  mere 
chance,  but  have  been  developed  under  the  guidance  of  those 
theoretical  views  concerning  the  constitution  of  the  coal-tar 
colors  which  have  been  wrought  out  by  modern  chemistry. 

METHODS. 
Selection  of  Colors. — In  consequence  of  the  great  number 
of  these  colors  and  the  constant  appearance  of  new  ones  in  the 
market,  it  has  been  impossible  to  test  all  or  even  the  greater 
portion.  A  selection  must  therefore  be  made,  and  it  will  be 
well  to  choose  first  those  which  are  in  some  manner  suspicious, 
from  having  caused  poisoning  in  their  intentional  or  uninten- 
tional use.  Moreover,  the  colors  most  suitable  for  practical  use 
must  be  taken  into  consideration.  Even  a  tolerably  complete 
list  of  such,  however,  is  not  easy  to  obtain,  since  the  employ- 
ment of  a  given  color  may  be  a  matter  of  fashion,  and  the  dif- 
ferent makers  have  some  interest  in  concealing  from  their  com- 
petitors which  colors  they  sell  in  largest  amount,  and,  further, 
the  consumer  cannot  always  find  out  what  colors  are  used  to 
bring  about  a  given  tint.  Perhaps  it  may  become  possible  to 
pronounce  upon  the  harmfulness  of  these  colors  by  a  sort  of  in- 
duction when  tests  have  been  made  of  many  colors,  including 


METHODS.  55 

the  most  various  groups,  without  subjecting  every  one  to  test. 
A  connection  between  chemical  composition  and  physiological 
action  is  certainly  to  be  expected. 

It  remains  to  be  considered  whether  the  toxicological  investi- 
gation should  be  limited  to  the  color  in  a  condition  of  absolute 
purity  or  only  to  the  commercial  form  of  it.  Tests  of  the  pure 
colors  have  preeminently  theoretical  significance,  since  the  degree 
of  toxic  action  and  the  relation  between  chemical  constitution 
and  physiological  effect  can  be  most  clearly  indicated.  Tests  of 
the  commercial  forms,  however,  have  greater  practical  value,  and 
only  when  a  commercial  article  is  found  to  be  poisonous,  will  it 
be  necessary  to  inquire  further  whether  the  poisonous  action  is 
an  essential  property  of  the  color  or  arises  from  accidental 
admixture.  This  point  will  be  made  more  clear  by  some  exam- 
ples. Fuchsin  and  its  congeners,  methyl  violet  and  malachite 
green,  are,  as  is  now  established,  almost  without  poisonous  action. 
Whoever  would  pronounce  an  arsenical  aniline  color  poisonous 
without  being  aware  of  its  arsenical  contamination,  would  easily 
fall  into  the  error  of  assuming  that  all  colors  analogous  to  fuchsin 
would  be  poisonous.  The  reverse  is  the  case  with  the  poisonous 
dinitrocresol  (saffron-substitute).  The  commercial  preparation 
contains  usually  about  forty  per  cent,  of  ammonium  chloride. 
This  addition  does  not  develop  the  poisonous  action  of  the 
color,  but,  as  is  obvious,  diminishes  it  materially.  Therefore, 
according  to  the  purpose  of  the  investigation,  whether  it  lean 
toward  theoretical  or  practical  information,  the  toxicological 
experiment  must  deal  either  with  the  pure  product  or  the  com- 
mercial form.  Should  the  commercial  article  be  found  poisonous, 
a  further  inquiry  will  be  needed  to  determine  if  it  can  be  made 
harmless  by  the  removal  of  any  impurities. 

Selection  of  the  Animals  for  Experiment. — Only 
rarely  will  the  toxicologist  be  able  to  make  researches  as  to  the 
effect  on  human  beings.  At  the  most,  a  case  of  poisoning  which 
has  come  to  chemical  or  legal  notice  will  be  investigated  scien- 
tifically. Investigations,  as  far  as  they  have  practical  value  in 
relation  to  the  human  organism,  must  be  carried  out  on  animals 


56  THE    COAL-TAR   COLORS. 

which  in  their  organization  and  chemical  functions  are  as  near 
as  possible  similar  to  human  beings.  Physiologists  know,  and  it 
will  not  be  necessary  for  me  to  stop  to  establish  the  fact,  that 
these  requirements  are  best  fulfilled  by  the  dog.  The  ape,  by 
reason  of  costliness,  scarcely  comes  into  consideration.  It  is 
naturally  of  great  scientific  interest  to  examine  the  effect  of  any 
material  upon  as  large  as  possible  a  number  of  animals  of  vari- 
ous types.  Even  the  higher  and  lower  plants  may  be  taken  into 
consideration  in  these  experiments.  It  must  also  not  pass  un- 
noticed that  occasionally  conclusions  may  be  drawn  from  experi- 
ments on  other  animals.  For  instance,  for  preliminary  researches, 
frogs  and  rabbits  have  value  for  economical  reasons.  The  con- 
clusions derived  from  such  experiments  must  be  accepted  with 
great  deliberation,  since  it  happens  that  rabbits  will  bear  without 
injury  doses  which  will  seriously,  nay,  even  fatally  act  upon  the 
dog,  as  I  have  already  shown  to  be  the  case  with  Martins'  yellow. 
Fishes,  for  instance,  are  only  affected  after  several  hours  by  doses 
of  curara  to  which  frogs  quickly  succumb.  Chickens  bear  Tnore 
than  ten  times,  Guinea  pigs  more  than  three  times,  the  dose  of 
strychnine  that  is  fatal  to  rabbits.  Human  beings  are  more  sensi- 
tive to  morphine  than  are  Guinea  pigs.  These  and  similar  facts 
serve  to  make  us  cautious  in  interpreting  results  obtained  in 
experiments  on  dogs.  It  is  only  because  we  have  no  other  satis- 
factory method,  that  we  use  the  dog  as  the  animal  for  experiment 
and  apply  the  results  thus  obtained  to  the  human  being. 

Manner  of  Administration. — Of  course,  only  exactly 
measured  and  weighed  doses  of  the  material  of  which  the  effect 
is  to  be  studied,  should  be  administered  to  the  animal.  This  is 
necessary  not  only  in  order  that  the  results  obtained  by  one 
experimenter  may  be  susceptible  of  confirmation  by  another,  but 
more  especially  because  most  materials  do  not  act  the  same  in 
small  as  in  large  doses.  Further,  the  material  to  be  tested 
should,  whenever  possible,  be  administered  in  dissolved  form.  In 
case  a  suitable  solvent  is  not  available,  the  material  should  be 
given  in  fine  powder,  or  suspended  in  water  or  other  liquid.  The 
selection  of  the  solvent  is  consequently  of  importance.     Such 


METHODS.  57 

liquids  only  are  applicable  as  are  either  without  action  when  ad- 
ministered in  moderate  quantity,  or  at  least  of  but  feeble  effect  : 
water,  very  dilute  acids,  alkalies,  or  salt  solution  are  suitable. 
Alcoholic,  ethereal,  and  similar  solutions  have  but  a  limited 
application  and  must  not  be  employed  unless  absolutely  neces- 
sary. In  doubtful  cases,  control  experiments  are  indispensable. 
Omitting  special  cases,  a  substance  may  be  administered  in  four 
different  ways  :  by  the  mouth,  by  direct  injection  into  blood,  by 
hypodermic,  and  by  endermic  application. 

(i)  Administration  by  the  Mouth. — Administration  by  the 
mouth  is  to  be  preferred  unless  special  reasons  to  the  contrary 
exist.  This  is  best  accomplished  by  means  of  the  food.  Fre- 
quently, however,  the  animal  refuses  to  eat  food  mixed  with 
foreign  matters.  In  such  a  case  it  can  either  be  introduced  by 
force,  or  the  oesophageal  tube  can  be  used.  The  latter  consists 
of  an  elastic  rubber  tube  of  a  diameter  corresponding  to  that  of 
the  gullet,  the  upper  end  terminating  in  a  funnel.  The  intro- 
duction of  the  apparatus  requires  the  aid  of  an  assistant,  but 
generally  does  not  involve  much  difficulty.  It  is  best  that  any 
solution  introduced  directly  into  the  stomach  by  this  apparatus, 
should  be  warmed  to  blood  heat.  The  quantity  of  liquid  intro- 
duced should  not  exceed  thirty  to  fifty  c.c.  even  with  large  dogs. 
Vomiting  may  easily  be  produced  if  larger  quantities  are  intro- 
duced. In  order  to  diminish  the  irritating  action  of  the  sub- 
stances administered,  a  soothing  menstruum  such  as  milk  or  pep- 
tone solution  should  be  employed.  Vomiting  takes  place  more 
quickly  on  an  empty  stomach  than  with  one  filled  with  food. 
The  oesophageal  sound  can  be  employed  with  good  results  for 
pumping  out  the  stomach.  The  action  can  be  assisted  by 
pressure  over  the  region  of  the  stomach  and  by  suction. 

(2)  Injection  into  the  Blood — /.  <?.,  intravascular  administra- 
tion. Injection  into  the  blood  requires  the  exposure  of  a  vein 
or  an  artery,  an  operation  that  should  only  be  performed  by  a 
trained  hand.  Most  substances  produce  their  effect  more  quickly 
and  more  powerfully  through  the  blood  than  through  the 
stomach,  and  in  such  injections  the   solvent  plays  a  most  im- 

5 


58  THE   COAL-TAR   COLORS. 

portant  part.  Watery  solutions,  for  instance,  produce  coagula- 
tion of  the  blood  and  destroy  the  experiment.  The  employment 
of  a  dilute  solution — say  about  0.75  per  cent. — of  sodium  chlo- 
ride is  more  satisfactory.  The  introduction  of  large  volumes 
of  water  into  the  blood-vessels  will  produce  spasm. 

(3)  Hypodermic  Ad?nmistration,  i.  e.,  dissolved  substances 
introduced  beneath  a  fold  of  skin  by  means  of  a  suitable  syringe. 
The  back  is  usually  chosen,  or  some  point  on  the  surface  of  the 
body  which  cannot  be  reached  by  the  tongue.  The  skin  should 
be  shaved  at  the  point  at  which  the  injection  is  made,  cleaned, 
and  disinfected.  The  solution,  the  syringe,  and  the  canula 
must  be  sterilized.  The  injection  must  not  injure  the  deeper 
tissues  such  as  fascia  and  muscles.  Large  volumes  of  solution 
must  be  avoided.  Not  more  than  10  to  15  c.c.  should  be 
injected  at  one  point  even  with  large  animals.  The  effect  of  the 
hypodermic  method  is  generally  as  powerful  as  the  direct  injec- 
tion into  the  blood-vessels,  and  may  advantageously  replace  it. 

(4)  Endermic  Application. — Administration  of  material  by 
application  to  the  surface  of  the  skin,  is  but  little  employed  in 
experiments  on  animals,  since  the  absorptive  quality  of  the  un- 
broken skin  is  so  slight  that  some  investigators  have  denied  it 
entirely.  In  every  case  the  skin  must  be  shaved  and  a  point 
chosen  which  cannot  be  reached  by  the  tongue.  If,  how- 
ever, the  upper  layers  of  the  skin  are  removed  by  blistering,  or 
incisions,  and  wounds  are  made  on  the  skin,  substances  applied 
at  such  points  will  be  absorbed  into  the  lymph  or  blood.  We 
have  in  such  a  case  conditions  analogous  to  those  under  which 
a  color  or  a  mordant  on  a  fabric  in  direct  contact  with  the  skin 
may  produce  poisoning.  Many  substances,  for  instance,  quick- 
silver, may  be  forced  through  the  unbroken  skin  by  pressure. 

Diagnosis  of  Poisoning. — Of  the  various  symptoms  which 
may  be  exhibited  by  the  human  organism  under  the  influence  of 
poisoning,  the  most  important  series  is  almost  entirely  lost  in 
experiments  on  animals,  namely,  the  subjective  symptoms.  In 
animals  we  cannot  expect  to  appreciate  the  manifold  disturbances 
of  sensation  and  ideation,  feelings  of  discomfort,  slight  disturb- 


METHODS.  59 

ances  of  sight  and  hearing,  which,  among  human  beings,  may 
alone  constitute  a  clue  to  the  poisoning.  For  instance,  a  par- 
ticular form  of  local  anaesthesia  and  amaurosis  is  typical  of  lead 
poisoning.  Moreover,  the  recognition  of  the  objective  symp- 
toms of  poisoning,  especially  when  they  are  not  well  developed, 
depends  upon  an  exact  knowledge  of  the  special  nature  of  the 
animal  in  a  state  of  health.  Pulse  and  respiration  rate,  normal 
temperature  variations  in  different  portions  of  the  body,  amount 
and  number  of  the  discharges,  composition  of  the  secretions  and 
organs,  all  must  be  known  to  the  one  who  would  with  certainty 
detect  departures  from  the  standard.  Examination  of  the  urine 
is  of  special  diagnostic  value.  A  dark,  almost  black,  secretion 
is  discharged  in  carbolic  acid  poisoning ;  an  abundant  but  pale 
urine  occurs  in  various  disturbances  of  the  circulation.  A  high 
specific  gravity  indicates  increased  tissue  disturbances,  such  as 
occur  in  fever.  An  alteration  of  the  chemical  reaction  occurs 
after  the  administration  of  the  salts  of  the  organic  acids.  These 
are  converted  into  the  alkaline  carbonates  and  then  excreted. 
This  is  the  reason  that  the  secretion  in  the  case  of  vegetable 
feeders,  in  the  food  of  which  the  salts  of  the  organic  acids  are 
found,  gives  an  alkaline  reaction,  while  in  meat-eating  animals 
it  generally  exhibits  an  acid  or  neutral  reaction.  Moreover, 
changes  in  the  blood,  especially  in  the  blood- coloring  matter, 
may  serve  as  a  clue  to  the  detection  of  poisoning,  the  method 
involving,  as  a  rule,  the  employment  of  a  spectroscope.  Thus, 
in  cases  of  poisoning  by  illuminating  gas,  the  blood  may  con- 
tain in  addition  to  normal  haemoglobin,  the  carboxyhaemoglobin  ; 
after  large  doses  of  potassium  chlorate  or  potassium  ferricyanide, 
methtemoglobin  will  be  present.  Inhalations  of  hydrogen  sul- 
phide produce  a  characteristic  alteration  of  the  blood-coloring 
matter.  The  appearance  of  abnormal  ingredients  in  the  urine 
will  also  frequently  give  most  important  information.  Blood- 
coloring  matters  appear,  for  instance,  in  cases  of  poisoning  by 
hydrogen  arsenide ;  sugar  is  found  in  poisoning  by  carbon- 
monoxide  and  nitrobenzene ;  sulphates  are  wanting  after  toxic 
doses  of  carbolic  acid,  and  the  secretion  is  rich  in  phenol ;  albu- 


6o  THE   COAL-TAR   COLORS. 

min  is  frequently  referable  to  an  affection   of  the  kidneys,  as 
is  noted  in  poisoning  by  cantharides  and  /?-naphthol. 

Bile  acids  and  bile  coloring  matters  are  also  observed  in 
pathological  urines.  Scarcely  less  important  than  the  observa- 
tions on  the  living  creatures  is  the  anatomical  investigation  after 
death,  especially  with  a  view  to  determining  the  mode  of  action. 
Some  poisons  accumulate  in  the  organism  and  may  be  detected 
after  a  long  time.  Lead,  for  instance,  accumulates  in  the  bones, 
kidneys,  and  liver ;  copper,  principally  in  the  muscles  ;  arsenic 
in  the  intestines,  kidneys,  and  liver.  Many  poisons,  such  as 
acids  and  alkalies,  have  a  local  corrosive  action,  other  substances 
must  enter  the  general  circulation  before  they  can  produce 
pathological  changes.  To  the  latter  class  belongs  phosphorus, 
which,  on  the  one  hand,  modifies,  in  a  most  remarkable  manner, 
the  tissue  metabolism ;  on  the  other  hand,  brings  about  an  ex- 
tensive fatty  degeneration  of  liver,  kidney,  heart,  and  blood- 
vessels. There  are  also  many  poisons  that  produce  death  quickly 
without  any  pathological  changes,  that  are  up  to  the  ptesent 
time  recognizable  by  us.  These  can  be  classified  according  to 
the  points  at  which  their  effects  are  most  distinctly  manifested, 
into  heart,  nerve,  and  blood  poisons.  In  the  first  class  we  place 
muscarine  and  several  ptomaines  closely  related  to  it.  Among 
the  blood  poisons  we  enumerate  carbon  monoxide,  hydrogen 
sulphide,  amyl  nitrite.  In  the  third  class  we  find,  pre-eminently, 
hydrogen  cyanide;  further,  strychnine,  nicotine,  chloroform, 
curare,  and  probably  most  of  the  ptomaines.  I  may  here  point 
out  a  source  of  error  which  may  be  serious  in  observing  cases  of 
chronic  poisoning  in  animals,  that  after  a  long  time  have  per- 
ished or  been  killed  after  a  prolonged  delay.  I  refer  to  infection 
by  reason  of  unclean  instruments  and  unclean  and  insufficiently 
ventilated  places  of  confinement.  Only  the  greatest  cleanliness 
and  most  exact  anatomical  investigation  will  avoid  these  sources 
of  error.  From  this  brief  notice  concerning  the  diagnosis  of 
poisoning  it  will  appear  that  the  decision  as  to  whether  a  sub- 
stance is  or  is  not  poisonous  can  only  be  given  by  an  expert. 


SPECIAL   PART. 


NITROSO-COLORS. 

By  the  action  of  nitrous  acid  upon  certain  of  the  phenol 
derivatives  and  their  sulphonic  acids,  bodies  are  produced  which 
form  salt-like  combinations  with  iron,  nickel,  and  cobalt.  These 
have  coloring  qualities  and  are  tolerably  permanent.  Iron, 
nickel,  and  cobalt  can  be  detected  only  after  ashing  the  material. 
These  colors  probably  contain  the  dyad  isonitroso-group  NHO, 
and  are,  therefore,  preferably  called  isonitroso-colors.  The 
metals  substitute  the  hydrogen  atom  of  the  isonitroso-group. 
These  colors  dye  wool,  silk,  and  cotton  tolerably  fast.  They 
are  either  produced  upon  the  fibre,  as  in  the  color  known  as 
solid  green  (see  below),  or  the  fibre  is  impregnated  with  a  ready 
formed  color,  as  is  the  case  with  naphthol  green  B.  Investiga- 
tions as  to  the  effects  of  the  nitroso-colors  upon  the  animal 
organisms  are  apparently  not  yet  on  record. 

Dinitrosoresorcinol. 

This  compound,  preferably  called  diisonitrosoresorcinol,  is 
produced  by  the  action  of  sodium  nitrite,  at  a  low  temperature, 
upon  a  solution  of  resorcinol  in  dilute  acetic  acid.  According 
to  Kostanecki  it  has  the  following  constitution  : — 

O 1 

_N_0— H 

H— O— N — - 

It  crystallizes  from  hot  water,  or  hot  dilute  alcohol,  in  glistening, 
brownish-yellow  plates  containing  two  molecules  of  water  of 

6i 


62  THE   COAL-TAR   COLORS. 

crystallization.  It  dissolves  with  difficulty  in  cold  water,  better 
in  alcohol,  more  easily  in  hot  water  and  hot  alcohol.  It  is  in- 
soluble in  benzene  and  ether.  It  explodes  lightly'at  115°.  The 
alcoholic  solution  quickly  becomes  brown  when  exposed  to  the 
air. 

Typical  Reactions. — The  green  color  which  the  ferrous  salts 
produce  with  the  aqueous  solution  is  a  test  for  this  body.  This 
green  solution  is  bleached  by  reducing  agents.  The  dye  pro- 
duces, on  cotton,  mordanted  with  iron  salts,  a  dark  green,  which 
is  fairly  fast  to  soap  and  light.  The  color  thus  produced  is 
known  as  resorcinol  green,  Alsace  green,  or  solid  green. 

Exp.  I. — Dog  weighing  11,550  grams.  June  i8th,  two  grams  in  a 
small  amount  of  sodium  hydroxide,  administered  by  the  cesophageal 
tube.  June  19th,  animal  lively  ;  urine  scanty  ;  neutral  ;  dark  brown  ; 
producing  with  ferrous  salts  a  dark  green  color  not  destroyed  by  dilute 
acetic  or  muriatic  acid.  Two  grams  similarly  administered.  Urine 
600  c.c. ;  dark  brown,  traces  of  albumin.  Iron  reaction  very  distinct, 
slightly  alkaline,  Fehling's  solution  not  reduced.  June  20th,  two  grams 
as  usual;  animal  lively.  June  21st,  three  grams  ;  animal  lively  ;  no 
albumin.  June  22d,  condition  same;  weight,  11,140  grams;  loss 
about  400  grams  ;  experiment  relinquished. 

Exp.  2. — Dog  weighing  5500  grams.  July  13th,  one  gram  by  the 
tube.  July  14th,  very  little  eaten  ;  urine  dark  brown,  almost  black. 
With  ferrous  sulphate  produces  green  color  and  in  time  a  green  pre- 
cipitate. July  15th,  two  grams  by  the  tube.  July  i6th,  urine  colored 
green  by  ferrous  oxide  ;  no  albumin  ;  no  reduction  of  alkaline  solu- 
tion. Acids  produce  a  black  flocculent  precipitate.  July  17th,  ani- 
mal lively ;  three  grams  administered  ;  urine  deep  black  in  color. 
July  19th  and  20th,  animal  lively;  relinquished;  urine  contained 
some  albumin  and  produced,  with  dilute  sulphuric  acid,  a  brown  floc- 
culent precipitate.  This  was  collected  on  a  filtrate  and  was  found  to 
be  tolerably  easily  soluble  in  water,  and  again  precipitated  from  the 
filtered  solution  by  dilute  sulphuric  acid.  This  body  was  colored  green 
by  ferrous  salts.  The  filtrate  from  the  precipitation  by  acids  did  not 
produce,  even  after  neutralization,  any  green  color  with  ferrous  salts.* 


*  I  will  refer  elsewhere  to  this  flocculent  precipitate,  as  well  as  to  another 
substance  which  is  soluble  in  ether. 


NITROSO-COLORS. 


63 


Exp.  J.— Dog  weighing  5250  grams.  July  4th,  one  o'clock  in  the 
afternoon,  one  gram  dissolved  in  about  ten  c.c.  of  water,  assisted  by 
sodium  hydroxide,  introduced  beneath  skin  of  back.  In  the  evenino- 
the  animal  was  very  weak.  Urine  50  c.c. ;  almost  black.  No  green 
color  produced  by  ferrous  salts.  Sulphates  present,  also  traces  of 
albumin.  On  adding  an  acid,  a  brown  flocculent  precipitate  ap- 
peared which  was  soluble  in  alkalies.  On  distilling  in  hydrochloric 
acid,  no  substance  precipitable  by  bromine  water  passed  into  the  dis- 
tillate. July  5th,  animal  very  dull,  refused  all  food  and  died  about  two 
o'clock  in  the  afternoon.  Post  mortem  made  on  July  6th.  Body 
rigid ;  all  abdominal  organs  hyperaemic  ;  lung  hyperasmic  ;  heart 
contained  a  good  deal  of  non-coagulated  blood.  Vessels  of  the  cere- 
bral membrane  strongly  injected ;  brain  substance  oedematous. 
None  of  the  organs  tested  exhibited  the  green  color  with  ferrous 
salts. 

According  to  the  above  experiments,  diisonitrosoresorcinol  is 
not  dangerous  to  dogs  when  administered  by  the  stomach  even 
in  large  doses,  while  hypodermic  administration  proves  fatal 
within  twenty-four  hours  in  the  proportion  of  0.19  grams  per 
kilogram  of  the  body-weight. 

Naphthol  Green  B. 
Naphthol  green    B,  sodium    ferrous    nitrosonaphtholsulphon- 
ate,  is  produced  from  Schaeffer's  acid  O^-naphtholmonosulphonic 
acid)  by  the  action  of  nitrous  acid.     According  to  G.  Schultz, 
it  has  the  following  constitution  : — 


NaSO 


XaSO, 


The  commercial  article,  as  prepared  by  L.  Cassella  in  Frankfurt 
o.  M.,  is  a  dark  green  powder,  easily  soluble  to  a  green  solution 
in  water. 

Typical  Reactions.  — Sulphuric  acid  added  to  the  powder  pro- 
duces a  yellow  color,  no  precipitate  appearing  on  diluting  with 
water.  Dilute  acids  do  not  alter  the  solution  in  water.  Con- 
centrated acids  produce  a  yellow  color.     Alkalies  restore   the 


64  THE    COAL-TAR   COLORS. 

green  color  except  when  the  acid  has  been  acting  for  a  consider- 
able time.  The  green  solution  becomes  yellow  on  being  heated 
with  sodium  hydroxide.  Ether  shaken  with  alkaline  solution 
does  not  take  up  the  color.  The  green  solution  bleaches  ulti- 
mately when  heated  with  stannous  chloride  and  hydrochloric 
acid.  The  powder  heated  on  platinum  foil  leaves  a  residue  con- 
taining ferrous  sulphide. 

I  am  indebted  to  Messrs.  L.  Cassella  &  Co.  for  the  sample  of 
naphthol  green  B  with  which  the  experiments  given  below  were 
made,  which  show,  so  far  as  the  administration  by  the  stomach 
is  concerned,  the  material  to  be  harmless. 

Exp.  I. — Dog  weighing  5800  grams,  the  urine  of  which,  on  May 
13th  and  14th,  contained  traces  of  albumin.  May  15th,  one  gram  of 
naphthol  green  B,  in  small  quantity  of  water  administered  by  the  tube. 
May  i6th,  animal  quite  lively;  conjunctiva  stained  intensely  green  ; 
urine  greenish.  One  gram  as  usual.  May  17th,  one  gram ;  urine 
green.  May  i8th,  five  grams  by  the  tube  ;  animal  lively.  May  19th, 
appetite  undisturbed  ;  animal  lively  ;  relinquished. 

Exp.  2. — Dog  weighing  4800  grams.  May  12th  to  14th,  urine  free 
from  albumin.  May  15th,  naphthol  green  B,  two  grams  by  the  tube  ; 
urine  dirty  yellowish  green  ;  no  albumin  ;  no  iron  by  the  usual  re- 
agents. After  boiling  for  three-fourths  of  an  hour  with  fuming  nitric 
acid  only  traces  of  iron  could  be  detected.  May  i6th,  animal 
normal.  May  17th,  two  grams  by  the  tube;  condition  still  un- 
changed ;  eats  heartily ;  urine  yellowish  green  ;  no  sugar;  no  albumin. 
May  i8th,  animal  quite  lively;  fasces  normal,  but  colored  green.  The 
watery  extract  gives  a  green  reaction  with  sodium  or  ammonium 
hydroxide,  and  red  with  acids.  The  yellowish  green  urine  behaves 
in  the  same  manner  with  acids  and  alkalies ;  no  albumin  ;  no  sugar. 
On  standing,  the  surface  of  urine  became  almost  black.  By  mistake 
the  animal  received  two  grams  of  safranin,  and  the  experiment  was 
discontinued. 

Exp.  J. — Dog  weighing  5650  grams.  May  20th  to  23d,  no  albumin 
in  urine.  May  24th,  two  grams  dissolved  in  twenty-five  c.c,  admin- 
istered hypodermically  ;  animal  quite  lively,  taking  food  well.  Con- 
junctiva, gums,  and  mucous  membrane  of  the  jaw  colored  green. 
May  25th,  two  grams  in  twenty-five  c.c.  hypodermically,  animal 
lively.  May  26th,  27th,  and  28th,  the  same.  May  29th,  animal  lively; 
no  abscesses ;  relinquished. 


NITROSO-COLORS.  65 

Exp.  4. — Dog  weighing  5015  grams.  May  22d  to  24th,  doubtful 
traces  of  albumin.  May  25th,  two  grams  in  twenty-five  c.c,  hypo- 
dermically ;  twenty  minutes  after  the  injection,  conjunctiva,  mucous 
membrane  of  the  jaws  and  gums  were  colored  green.  Animal  lively; 
urine  scanty,  intensely  green  in  color.  May  26th,  two  grams  hypo- 
dermically  ;  animal  lively.  May  27th  and  28th,  two  grams,  similarly; 
urine  intensely  red  when  acidified.  May  29th,  animal  lost  weight. 
No  injection  ;  wool  is  colored  intensely  dark  green  by  the  urine 
slightly  acidulated  with  sulphuric  acid.  May  30th,  animal  weak  and 
feverish  ;  inner  surface  of  the  pinna  green,  as  well  as  conjunctiva. 
June  1st,  many  abscesses  on  the  back.  June  2d,  animal  dead.  Six 
pus  sacs.  Post-mortem  presented  same  appearance  as  in  following 
experiment, 

Exp.  5. — Dog  weighing  5600  grams.  May  i8th,  hypodermic  injec- 
tion ;  in  twenty  minutes  conjunctiva  became  intensely  green.  May 
19th,  similarly.  Urine  intensely  green.  May  20th  and  21st,  similarly, 
colors  wool  intensely  green.  May  22d,  animal  lively;  no  abscesses; 
weight  5450  grams,  therefore  about  150  grams  lost.  May  24th,  several 
abscesses  on  the  back.  May  26th,  animal  very  weak ;  killed.  Post- 
mortem :  Three  large  abscesses  beneath  skin  on  back,  from  which 
on  pressure  a  greenish  non-offensive  pus  escaped.  Subcutaneous 
cellular  tissue  and  the  serous  membranes,  peritoneum,  pericardium, 
endocardium,  and  pleura,  colored  deep  green.  Liver  and  spleen  also 
colored  green.  In  the  kidneys,  the  glomeruli  were  not  colored,  but 
the  uriniferous  tubules  were  green. 

Exps.  I  and  2,  in  which  two  to  five  grams  per  day  of  the 
color  were  introduced  directly  into  the  stomach,  demonstrated 
its  harmlessness  in  this  method  of  administration.  On  the 
other  hand,  in  the  hypodermic  administration,  in  two  out  of 
three  cases,  abscesses  and  septic  fever  were  induced.  Infection 
by  means  of  the  syringe  is  unlikely,  since  other  animals  for 
which  the  same  instrument  was  employed,  remained  free  from 
abscesses.  The  places  of  confinement  also  seemed  free  from  sus- 
picion. I  must  rather  regard  the  color  as  poisonous  when 
applied  hypodermically,  and  assume  that  in  the  third  experiment 
the  animal,  which  seemed  in  good  health  when  relinquished  had 
not  been  kept  sufficiently  long  under  observation.  The  color- 
ation of  the  conjunctiva  and  the  inner  surface  of  the  pinna 
6 


66  THE    COAL-TAR   COLORS. 

in  about  twenty  minutes  after  the  injection,  is   an    interesting 
physiological  phenomenon. 

NITRO-COLORS. 

Nitro-colors  contain  the  monad  nitro-group  NO2.  They  are 
produced  by  the  action  of  nitric  acid  upon  the  benzene  deriva- 
tives (nitration)  and  are,  like  most  nitro-compounds,  more  or 
less  explosive  by  heat  or  percussion.  Reducing  agents  convert 
them,  as  a  rule,  into  colorless  amido-derivatives.  Picric  acid, 
for  instance,  a  nitro-compound,  produces  by  proper  reduction 
triamidophenol,  an  amido-body. 

The  nitro-colors  are  mostly  orange  or  yellow-colored  salts  of 
nitro-compounds.  They  dye  wool  and  silk  the  corresponding 
color.  They  serve  this  purpose  only  in  a  restricted  degree  at 
the  present  time,  since  they  have  been  replaced  by  faster  colors. 
Picric  acid  is  by  far  the  most  used  of  the  nitro-colors  and  has 
long  been  known  to  be  poisonous.  With  the  exception  of  this, 
the  use  of  which  is  now  prohibited  by  Imperial  enactment, 
these  nitro-colors  are  now  largely  employed  for  coloring  food. 
Most  nitro-colors,  that  is  the  salts  of  the  nitro-compounds,  are 
not  very  freely  soluble  in  water.  * 

The  watery  solution  of  these  colors  is  mostly  precipitated, 
even  when  largely  diluted,  by  ammoniacal  copper  solution. f 
Warming  with  potassium  cyanide  generally  produces  the  so-called 
iso-purpuric  acid  reaction.  The  copper  salt  of  brilliant  yellow 
(Schoellkopf )  and  dinitrocresol  are  very  easily  soluble,  and  are 
therefore  precipitated  only  after  long  standing  or  not  at  all. 

The  following  table  will  serve  for  the  recognition  of  the  more 

*  Colors  which  contain  a  nitro-group  are  not  necessarily  nitro-colors.  We 
include  in  the  group  rather  those  bodies  the  color  of  which  depends  upon 
the  presence  of  the  chromophorous  nitro-group.  The  nitro-azo-colors,  for 
instance,  belong  to  the  azo-group,  since  the  azo-group,  —  N  =  N  — ,  not 
the  nitro-group,  is  the  characteristic  structure. 

I  The  behavior  of  the  following  colors  with  ammoniacal  copper  solution 
was  tested  by  the  author  :  picric  acid,  dinitrocresol,  Martius'  yellow,  naphthol 
yellow  S,  brilliant  yellow,  aurantia. 


liriTRO-COLORS.  67 

important  nitro-colors.     The  solution  to  be  tested  must   contain 
at  least  i  per  cent,  of  a  salt  of  the  color. 

The  watery  solution  of  the  color  is  treated  with  sodium 
hydroxide. 

(A)  A  precipitate  appears  either  promptly  or  after  standing. 

(i)  The  original  solution  produces  with  hydrochloric  acid  a  pre- 
cipitate soluble  in  ether  to  a  pale  yellow  color.  With  ferric  chlo- 
ride a  flocculent  yellowish-white  precipitate  is  produced.  The 
substance  is  free  from  sulphur  :  Martius'  yellow. 

(2)  The  original  color  remains  clear  upon  addition  of  hydro- 
chloric acid  and  becomes  a  bright  green.  The  original  solution 
is  momentarily  colored  red-brown  by  ferric  chloride,  then  per- 
manently dark  green.     The  body  contains  sulphur  : 

Brilliant  yellow  (Schoellkopf). 

(B)  The  solution  treated  with  sodium  hydroxide  remains 
clear. 

(i)  Amraoniacal  copper  solution  produces  no  precipitate,  or 
only  after  long  standing. 

Hydrochloric  acid  bleaches  the  original  solution.  Ferric 
chloride  produces  a  flocculent  precipitate  easily  soluble  in  water. 
On  boiling  with  ferric  chloride,  the  solution  becomes  red  ;  on 
cooling  a  flocculent  precipitate  is  separated  : 

Dinitrocresol  {saffron-substitute') . 

(2)  With  ammoniacal  copper  solution  a  precipitate,  mostly 
crystalline,  is  formed. 

Hydrochloric  acid  produces  a  precipitate  in  the  original  solu- 
tion, which  is  soluble  in  ether  to  a  yellow  color  :  Auraiitia. 

Hydrochloric  acid  produces  no  precipitate  in  the  original  solu- 
tion. By  reduction  with  stannous  chloride  and  hydrochloric 
acid,  and  subsequent  addition  of  ferrous  chloride,  a  golden  yellow 
solution  is  produced  :  Naphthol yellow  S. 

By  reduction  with  hydrochloric  acid  and  stannous  chloride, 
and  subsequent  addition  of  ferrous  chloride,  a  blue  solution  is 
produced  :  Picric  acid. 


68  THE    COAL-TAR    COLORS. 

Picric  Acid. 

This  is  produced  by  the  action  of  nitric  acid  upon  phenolsul- 
phonic  acids,  ortho-  or  paranitrophenol,  a-  or /5-dinitrophenol  and 
certain  resins.  The  action  of  nitric  acid  upon  silk,  wool,  leather, 
and  similar  substances  also  gives  rise  to  picric  acid.  The  com- 
mercial article  is  almost  entirely  prepared  by  the  action  of  nitric 
acid  upon  phenolsulphonic  acid  :  — 
HO  HO 


+  3HNO3  = 

NO. 


HSO3  NO2 


NO, 


+    H,SO,  +  H^O 


Pure  picric  acid  crystallizes  from  water  in  pale  yellow  shining 
plates,  from  ether,  in  rhombic  prisms.  By  cautious  heating  it 
sublimes  unchanged,  but  strongly  heated,  it  explodes.  It  melts 
at  122.5.  It  is  difficultly  soluble  in  cold  water  ;  easily  soluble  in 
hot ;  also  in  alcohol,  ether,  and  benzene.  These  solutions  are 
yellow  and  intensely  bitter.  Picrates  explode  by  percussion  and 
on  heating.  Sodium  picrate  is  much  more  soluble  than  the 
potassium  salt. 

Typical  Reactio7is. — In  concentrated  sulphuric  acid  the  pow- 
der dissolves  without  color,  and  the  watery  solution  is  not 
changed  by  a  few  drops  of  dilute  hydrochloric  acid.  (Distinc- 
tion from  brilliant  yellow,  Martins'  yellow,  aurantia,  and  dinitro- 
cresol.)  Ether  shaken  with  the  acid  solution  extracts  the  picric 
acid  and  becomes  yellow  in  color;  potassium  cyanide  added  to 
this  solution  produces  a  red-brown  color.  The  test  with  potas- 
sium cyanide  is  due  to  formation  of  isopurpuric  acid  ;  it  can  also 
be  applied  to  watery  solution  of  the  color.  This  isopurpuric 
reaction  is  shown  by  all  the  nitro-colors  tested.  Picric  acid, 
when  treated  with  ammoniacal  copper  sulphate,  consisting  of 
equal  volumes  of  copper  sulphate  solution  (i  :  12)  and  ammonium 
hydroxide,  produces,  even  in  dilute  solutions,  a  yellow  crystal- 
line precipitate,  which  dissolves  in  hydrochloric  acid  to  a  clear 
liquid  (distinction  between  Martins'  yellow  and  aurantia).  The 
solution  in  hot  water  is  colored  dark  brown-red  by  boiling  with 


NITRO-COLORS.  69 

potassium  cyanide.  Copper  picrate  is  insoluble  in  alcohol. 
Ammonium  picrate  produces  with  sodium  hydroxide  no  precipi- 
tate (distinction  from  brilliant  yellow).  Picric  acid,  by  reduc- 
tion with  alcoholic  solution  of  ammonium  sulphide,  forms  a 
red  solution  of  picramic  acid  (dinitroamidophenol).  Hydro- 
chloric acid  solution  of  stannous  chloride  produces  triamidophe- 
nol,  which, by  addition  of  small  amount  of  ferric  chloride,  becomes 
diimidoamidophenol  (distinction  from  all  remaining  nitro- 
colors).  Ferric  chloride  produces  with  picric  acid  a  reddish 
yellow  precipitate,  rather  easily  soluble  in  water.  To  detect  the 
acid  in  textiles  and  foods,  it  must  be  extracted.  This  is  best 
accomplished  by  producing  an  ethereal  solution  and  shaking  it 
with  a  little  alkali.  The  alkaline  picrate  can  then  be  tested  for 
by  reactions  numbers  two,  four,  and  seven  just  mentioned. 

Applicafio7is. — Picric  acid  was  formerly  largely  used,  either 
alone  or  in  association  with  other  colors,  for  dyeing  silk,  wool 
and  artificial  flowers,  yellow.  It  has  also  been  employed  in 
foods,  and  has  had  some  applications  in  medicine.  In  Germany 
its  employment  for  coloring  food  is  forbidden  by  the  Imperial 
enactment  of  1S88,  on  account  of  its  poisonous  character.  The 
poisonous  qualities  of  picric  acid  have  been  much  exaggerated. 
Erb  gave  a  rabbit  weighing  1700  grams,  .06  gram  of  potassium 
picrate  daily  for  ninety  days.  Slight  loss  of  weight  and,  occa- 
sional diarrhoea  were  noted,  but  nothing  more  serious.  A 
rabbit  weighing  2065  grams  died  at  the  end  of  nineteen  days, 
after  having  taken  2.52  grams  of  the  substance. 

A  very  young  dog  received  daily,  from  April  21st  to  26th,  .24  gram 
of  sodium  picrate.  From  April  28th  to  May  9th,  .36  gram  daily  of 
the  same,  and,  therefore,  received  in  the  course  of  about  two  weeks 
5.76  grams  of  sodium  picrate  without  the  appearance  of  any  serious 
phenomena.  May  13th,  the  same  animal  received  in  one  dose  1.2 
grams  of  sodium  picrate.  On  the  following  day  it  was  quite  weak, 
marked  diarrhoea  and  dyspnoea  appearing.  May  14th,  .6  gram 
were  administered,  which  caused  vomiting.  About  evening  .36  gram 
were  administered.  May  1 5th,  animal  lively  ;  .24  gram  was  again 
given,  and  in  the  evening  of  the  same  day,  .72  gram.  ]May  i6th, 
marked  weakness  was  manifested,  and  .16  gram  of  the  salt  was  ad- 


70  THE   COAL-TAR    COLORS. 

ministered.  Marked  vomiting  ensued.  On  May  17th,  .72  gram  was 
given.  May  i8th  and  19th,  animal  had  distinctly  recovered,  and, 
with  the  exception  of  a  strong  yellow  tinge  of  the  conjunctiva  and 
skin,  no  abnormal  conditions  were  manifest.  Not  until  May  20th  did 
the  animal  finally  succumb,  after  the  administration  of  1.32  gram  of 
potassium  picrate.  This  dog  had  taken  the  enormous  dose  of  10.5 
grams  in  the  course  of  four  weeks,  of  which  .9  gram  of  sodium  and 
potassum  picrate,  respectively,  had  been  administered  hypoder- 
mically.  Even  after  the  administration  of  8.5  grams  the  dog  was 
tolerably  well.  Dogs  are,  therefore,  resisting  to  this  substance, 
notwithstanding  the  prostration  and  the  blood  disorganization. 
(Note. — .6  gram  administered  May  14th  was  not  taken  into  con- 
sideration in  the  experiment,  being  mostly  expelled  by  vomiting. 

We  are  also  tolerably  familiar  with  the  action  of  picric  acid 
and  picrates  upon  human  beings  by  reason  of  the  therapeutic 
applications  and  also  from  some  cases  of  poisoning.  Daily  doses 
from  .54  to  .90  gram  of  potassium  picrate  are  easily  borne  by 
healthy  adults  for  a  considerable  time.  Generally  after  twenty- 
four  hours  a  distinct  yellow  tint  of  the  skin  and  conjunctiva 
ensues.  The  urine  is  dark-colored  and  contains,  among  other 
substances,  small  amounts  of  the  acid.  Children  and  weak  adults 
bear  picric  acid  badly.  Picric  acid  was  formerly  employed  in 
place  of  quinine  in  cases  of  intermittent  fever.  Doses  of  from 
0.3  to  0.9  gram  were  administered  three  times  per  day,  appar- 
ently without  results.  It  has  also  been  employed  as  an  anthel- 
mintic. It  is  valueless  for  the  removal  of  trichinae  and  cysticerci, 
but  has  been  commended  in  the  treatment  of  some  other 
intestinal  parasites.  It  has  also  been  employed  in  the  treatment 
of  coughs,  dyspepsia,  chlorosis,  etc.  Few  cases  of  picric  acid 
poisoning  are  recorded,  and  none  of  them  were  fatal.*  In  a 
case  reported  by  Adler,  a  school-girl,  aged  sixteen,  took  from 
three  to  five  grams  of  the  acid.  Vomiting  and  diarrhoea  occurred 
promptly.     She  became  chlorotic  and  the  skin  of  the  whole  body 

*  L.  Lewin  ("Lehrb.  f.  Toxicol,"  1885,  p.  229)  found  record  of  only  three 
cases  of  poisoning  by  picric  acid.  Since  then  the  case  quoted  above,  reported 
by  Adler,  has  occurred. 


NITRO- COLORS.  7 1 

became  intensely  dark  yellow,  almost  brown,  so  that  the  patient 
appeared  to  be  jaundiced.  The  visible  mucous  membrane  was 
pale.  The  fingers  of  both  hands  were  flexed  at  the  metacarpo- 
phalangeal articulations,  but  the  fingers  themselves  remained 
straight  and  rigid  and  could  not  be  actively  moved  by  the  patient. 
The  blood  contained  many  white  and  few  red  corpuscles.  Lud- 
wig  found  picric  acid  in  the  urine.  The  girl  recovered  in  about 
a  week. 

The  foregoing  statements  show  that  while  the  acid  must  be 
considered  poisonous,  its  injurious  character  is  far  less  than  has 
generally  been  assumed.  Nevertheless,  the  legal  prohibition  of 
its  use  as  a  coloring  matter  for  food  or  drink  is  just. 

Dinitrocresol.     Saffron-substitute. 

The  color  variously  known  as  saffron-substitute,  golden  yellow, 
Victoria  yellow,  Victoria  orange,  and  aniline  orange,  consists  of 
the  potassium  or  ammonium  salt  of  dinitrocresol.  It  is  obtained 
by  the  nitration  of  cresolsulphcnic  acid  : — 

CeH3(CH3)(HO)(HS03)  +  2HN03  = 
CeH,(CH3)(H0)(N0,),  +  H,SO,  +  H,0, 

and  corresponds  to  the  formula: — 

CeH,(CH3)(K0)(N0,),  or  C6H,(CH3)(NH,0)(NO,),. 

The  Victoria  yellow,  produced  by  the  nitration  of  orthocre- 
sol,  is  distinguished  by  its  yellow  color  from  the  redder  saffron- 
substitute  produced  from  paracresol.  The  potassium  and  am- 
monium salts  dissolve  in  alcohol  and  water  rather  easily.  The 
concentrated  solutions  are  orange  ;  by  dilution  they  become 
yellow.  The  dry  color  explodes  on  heating.  The  commercial 
article  is  mixed  with  about  forty  per  cent,  of  ammonium 
chloride  to  prevent  explosion  and  make  the  materials  transport- 
able. 

Typical  Reactions. — The  powder  dissolves  in  concentrated 
sulphuric  acid  without  color.  The  addition  of  water  produces 
no  precipitate  (distinction  from  Martius'  yellow).  The  watery 
solution  of  the  potassium  or  ammonium  salt   becomes  colorless 


72  THE    COAL-TAR   COLORS. 

or  weak  yellow  by  addition  of  hydrochloric  or  sulphuric  acid, 
and  the  free  dinitrocresol  separates  in  pale  yellow  needles  (dis- 
tinction from  picric  acid).  The  precipitate  is  soluble  in  alcohol. 
Ether  extracts  the  color  acid  from  the  acidified  solution  and 
becomes  pale  yellow  (distinction  from  picric  acid).  Alkali  added 
to  the  ethereal  solution  produces  a  yellowish  brown  color.  The 
aqueous  or  alcoholic  solution  of  the  color  produces  a  dark  brown 
on  heating  with  potassium  cyanide.  The  aqueous  solution  of 
the  commercial  saffron-substitute  is  not  precipitated  even  after 
prolonged  standing  by  the  above  mentioned  ammoniacal  copper 
solution  (distinction  from  Martius'  yellow,  naphthol  yellow  S, 
aurantia,  and  picric  acid).  Occasionally,  after  twenty-four 
hours,  a  small  amount  of  flocculent  precipitate  separates. 
(Weyl.)  (See  brilliant  yellow.)  The  dry  salts  of  dinitrocresol 
explode  when  heated.  Ferric  chloride  produces,  in  the  aqueous 
solution,  a  pale  yellow  precipitate  easily  soluble  in  water. 
Heated  with  ferric  chloride,  the  solution  becomes  red  ;  on  cool- 
ing a  flocculent  precipitate  separates.  Sodium  hydroxide*  pro- 
duces no  precipitate  (distinction  from  brilliant  yellow).  Hydro- 
chloric acid  solution  of  stannous  chloride  produces,  in  the 
presence  of  ammonium  hydroxide,  a  red  color  ;  in  the  presence  of 
ferric  chloride,  an  orange  yellow  solution  (compare  picric  acid). 

The  uses  of  these  colors  are  almost  entirely  limited  to  the 
coloring  of  food  and  drink,  such  as  noodles,  cakes,  and  liquors. 
The  orange  color  produced  by  dinitrocresol  on  silk  and  wool 
rubs  off  easily,  and  it  is,  therefore,  not  in  favor.  Saffron- 
substitute  is,  as  the  following  experiments  show,  a  powerful 
poison.  My  investigations  were  conducted  with  six  samples,  the 
sources  of  which  were  as  follows  : — 

(a)  From  the  collection  in  the  laboratory  of  organic  chem- 
istry at  the  Berlin  Polytechnic,  kindly  placed  at  my  disposal  by 
Professor  Liebermann.  This  sample  consisted  almost  entirely 
of  potassium  dinitrocresol. 

(^)  A  sample  kindly  furnished  by  Dr.  Martius,  of  Berlin. 

(c)  The  commercial  article  from  Schuster  &  Co.,  of  Eutrisch, 
near  Leipzig. 


NITRO-COLORS.  73 

(//)  The  commercial  article  from  Ed.  Sauppe,  in  Doebeln. 

{e)  The  commercial  article  from  M.  Mittenzwey,  in  Poelbitz. 

(/)  A  sample  from  the  case  of  poisoning  in  Bremerhaven. 

c,  d,  and  e  each  contain  about  forty  per  cent,  of  ammonium 
chloride. 

The  various  preparations  were  very  similar.  They  were  yel- 
lowish-red micro-crystalline  powders.  The  sample  from  the 
collection  of  the  Berlin  laboratory  consisted  of  distinct  crystals 
which  had  a  silver  lustre  in  reflected  light. 

Experiments  on  Rabbits. — Animals  to  which  .25  gram  of  dinitro- 
cresol  salt,  dissolved  in  a  small  quantity  of  water,  were  administered 
by  the  oesophageal  tube  exhibited  the  following  symptoms  :  For  a 
short  time  after  the  administration  they  were  not  visibly  depressed. 
They  hopped  about  the  room  and  showed  no  abnormal  condition. 
The  respirations,  however,  soon  became  more  rapid.  The  animals 
became  quiet,  and  occasionally  fell  to  one  side.  In  forward  move- 
ments, the  hind  limbs  dragged.  The  muzzle  touched  the  ground, 
but  could  again  be  raised,  and  the  animal  was  still  able  to  move  for- 
ward. The  pupils  were  generally  dilated,  in  some  cases  contracted 
just  before  death.  The  breathing  gradually  became  more  rapid, 
and  occasionally  ceased  for  a  time,  the  animal  at  this  time  lying  on 
one  side,  the  head  touching  the  ground.  The  eyes,  the  bulbs  of  the 
conjunctiva,  were  insensitive,  and  the  pupils  strongly  dilated.  The 
extremities  exhibited  twitchings.  Finally,  spasms  supervened.  As  a 
general  rule,  Cheyne-Stokes  respiration  occurred.  The  intervals  be- 
tween the  respirations  increased  slowly  until  they  reached  from  ten 
to  fifteen  seconds,  at  which  time  death  ensued  from  asphyxia.  Usually, 
the  head  was  drawn  backward  and  there  was  general  but  brief  spasm 
of  the  extensors.  In  two  cases,  Exps.  i  and  3,  as  the  annexed 
table  shows,  these  symptoms  ran  their  courses  in  from  twenty  to 
thirty  minutes,  and  in  these  cases  the  preparation  used  was,  as  stated 
above,  a  nearly  pure  potassium  dinitrocresol.     In  the  ninth  experi- 


74 


THE    COAL-TAR    COLORS. 


ment  death  occurred  after  two  hours.     The  following  notes  on  ex- 
periments will  give  more  precise  information  : — 

EXPERIMENTS  ON  RABBITS— ADMINISTRATION  BY 

STOMACH. 


No. 

Weight 

OF 

Animal. 

Amount  of 

Dose 

Actually  Ad- 

ministekeu. 

Proportion 
of  Dose  per 
Kilometre. 

Duration 

OF 

Case. 

Sample 
Used. 

I 

890 

0.24 

0.27 

10  minutes. 

a 

2 

670 

0.08 

0.12 

not  fatal. 

a 

3 

640 

0.16 

0.25 

15  minutes. 

a 

4 

670 

0.17 

0.25 

21          " 

b 

5 

1360 

0.34 

0.25 

30 

b 

6 

1880 

0.47 

0.25 

46         - 

c 

7 

750 

0.187 

0.25 

25 

c 

8 

680 

0.17- 

0.25 

143 

d 

9 

1797 

0.45 

0.25 

20         " 

d 

ID 

1610 

0.40 

0.24 

120         " 

f 

II 

1970 

0.50 

0.25 

165         " 

f 

12 

1870 

0.45 

0.24 

135 

f 

13 

1750 

0.42 

0.24 

140         " 

e 

14 

1690 

0.42 

0.25 

150 

e 

*  S"me  of  the  material  was  lost  in  the  administration. 

Exp.  4. — Rabbit  weighing  680  grams  received  .17  gram  of  the 
preparation  from  Ed.  Sauppe,  the  administration  taking  place  at 
12.22  P.M.  At  12.30  the  animal  was  not  yet  affected.  At  12.54  it 
had  become  still.  At  1.16  was  breathing  with  dilated  nostrils.  1.52, 
head  dropped  to  the  ground.  2.00,  long  respiratory  pauses.  2.10, 
Cheyne-Stokes  respirations,  pauses  of  from  ten  to  twelve  seconds. 
2.45,  death. 

Exp.  g.  Animal  weighing  1797  grams  received  .45  gram  of  the 
same  preparation  at  12.00  o'clock.  At  12.03,  marked  dyspnoea.  12.10, 
lateral  decubitus.  12.12,  chronic  spasm.  12.20,  head  bent  strongly 
backward.     12.25,  death. 

I  tested  the  hypodermic  action  of  the  preparation  from  Bremer- 
haven  only.  The  symptoms  were  as  given  above,  with  the  excep- 
tion that  death  occurred  more  quickly. 


NITRO-COLORS  75 

Exp.  /J. — A  rabbit  weighing  1825  grams  received  hypodermi- 
cally  .2  gram  of  the  Bremerhaven  preparation,  dissolved  in  luke- 
warm water,  the  proportion  being  .11  gram  per  kilogram  of  the  body 
weight.  The  injection  was  made  at  2.04.  At  2.10  there  was  marked 
dyspnoea  and  convulsive  movements;  strong  expiratory  efforts; 
marked  weakness ;  the  extremities  constantly  moved  to  and  fro 
beneath  the  body  of  the  animal.  2.40,  the  head  falls  to  the  side; 
eyes  remaining  widely  open,  3  o'clock,  animal  lies  quietly  on  the 
side  ;  deep  breathing  with  long  pauses  ;  almost  typical  Cheyne-Stokes 
respiration  ;  pupil  reflexes  wanting,  3.15,  death.  A  second  animal, 
to  which  only  .06  gram  per  kilo  of  body  weight  had  been  adminis- 
tered subcutaneously,  exhibited  marked  dyspnoea  and  escaped  fatal 
poisoning. 

An  autopsy  of  the  animal  killed  by  administration  by 
stomach  exhibited  marked  yellow  staining  in  that  organ.  Its 
contents  were  acidified  with  hydrochloric  acid  and  extracted 
with  ether.  The  ether  extract  was  colored  green  by  the 
presence  of  chlorophyll,  as  was  shown  by  the  spectroscope,  and, 
on  shaking  the  liquid  with  sodium  hydroxide,  the  latter  took  up 
a  body  which  was  soluble  in  alcohol  to  a  yellowish-red  color. 
The  green  ethereal  solution  showed  a  red  fluorescence.  The 
alkaline  solution,  being  freed  from  ether  by  warming  and  acidu- 
lated with  hydrochloric  acid,  deposited  a  crystalline  predipitate 
having  the  properties  of  dinitrocresol.  Most  of  the  viscera, 
especially  the  liver  and  lungs,  were  highly  congested. 

Experiments  on  Dogs.  — Admi?iistration  by  Stomach. — 
Animals  to  which  the  saffron-substitute  has  been  administered 
by  means  of  the  oesophageal  tube  exhibit  characteristic  symp- 
toms. At  first,  in  all  cases,  more  or  less  vomiting  occurs,  and 
diarrhoea  is  frequently  induced.  If  by  these  actions  the  greater 
part  of  the  poison  is  expelled  from  the  animal,  it  begins  in  from 
about  ten  to  fifteen  minutes  to  resume  the  normal  condition.  It 
runs  about,  responds  to  calls,  and  takes  food  readily.  Generally, 
however,  sufficient  of  the  dinitrocresol  remains  in  the  system  to 
develop  the  remaining  symptoms  of  poisoning.  In  such  cases 
the  vomiting  is  followed  in  about  ten  to  twenty  minutes  by  a 
peculiar  trembling  of  the  entire  frame.     Spasmodic,   and  fre- 


76  THE    COAL-TAR    COLORS. 

quently  ineffectual,  attempts  at  vomiting  occur,  with  the  discharge 
of  a  tough,  somewhat  yellow-colored  mucus.  The  breathing  is 
labored,  with  forced  expirations.  The  animal  is  unable  to  stand 
upright,  and  excessive  salivation  appears.  The  animal  then  falls 
upon  its  side,  and  clonic  spasms  of  the  extremities  occur,  during 
which  the  animal  paws  the  air.  Death  ensues  usually  in  the 
third  and  fourth  attacks.  The  following  are  details  from  some 
experiments  :  — 

Exp.  I. — Dog  weighing  6230  grams  received  at  12.20  p.m.,  Janu- 
ary 8th,  1888,  by  means  of  the  oesophageal  tube,  about  1.5  gram  of 
dinitrocresol  from  the  Polytechnic  laboratory,  the  material  being  dis- 
solved in  from  fifty  to  sixty  c.c.  of  lukewarm  water.  12.30,  frequent 
vomiting.  12.40,  marked  muscular  tremors.  The  animal  stood  up- 
right with  difficulty  and  continued  to  vomit.  12.45,  after  rapid 
spasmodic  efforts  at  vomiting  the  animal  lay  down.  12.49,  clonic 
spasms  while  lying  on  the  side.  12.52,  salivation,  diarrhoea,  i 
o'clock,  the  animal  was  sleeping.     2  o'clock,  completely  recovered. 

Exp.  3. — Dog  weighing  5500  grams  received  January  21st, .1888,  at 
12.10  P.M.,  30  grams  of  dinitrocresol,  same  sample  as  above,  adminis- 
tered by  the  oesophageal  tube.  12.15,  vomiting.  12.20,  diarrhoea. 
12.25,  animal  fell  upon  its  side  and  pawed  the  air  ;  renewed  vomiting, 
by  which  a  rather  tough  white  mucus  was  discharged.  12.27,  strong 
tonic  spasm  ;  the  animal  lay  on  the  side,  the  mouth  opened  by 
tetanic  spasm.  12.35,  third  spasmodic  seizure.  12.45,  fourth  spas- 
modic seizure.  12.50.  death  ;  muscles  stiff.  Post-mortem  showed 
very  little  material  in  the  stomach  except  a  few  crystals  of  dinitrocre- 
sol. Liver,  intestines,  and  lungs  hyperaemic.  No  methaemoglobin 
detected  in  the  blood. 

Exp.  5, — A  Newfoundland  dog  weighing  14500  grams  received  at 
1.55  P.M.,  January  22d,  .7  gram  of  dinitrocresol,  same  sample  as  above, 
administered  in  milk  by  means  of  the  oesophageal  tube.  2.20,  animal 
was  quiet.  2.35,  dyspnoea,  loud  complaining.  2.40,  salivation.  2.45, 
urine  passed  containing  dinitrocresol  salt.  2.46,  vomited.  2.50,  very 
restless.  3,  tonic  spasms  of  the  extremities,  loud  cries.  3.03,  vomit- 
ing. 3.15,  marked  dypsnoea,  animal  lying  upon  its  side;  strong, 
spasmodic  seizure  ;  animal  does  not  react  to  strong  irritation.  2.35, 
animal  lively.  2.31,  very  little  dyspnoea.  4,  completely  restored  (see 
further  experiment,  No.  7). 


NITRO-COLORS.  77 

A  summary  of  all  the  experiments  is  given  in  the  table  below. 
I  hoped  by  means  of  the  hypodermic  injection  to  avoid  the 
vomiting  brought  about  by  the  administration  by  the  stomach. 
The  experiments  showed,  however,  that  this  expectation  could 
not  be  realized. 

Exp.  6. — Dog  weighing  6230  grams  received  subcutaneously  Jan- 
uary 24th,  1888,  1. 2 1  p.  M.,  O.I  gram  of  dinitrocresol,  same  sample  as 
above,  dissolved  in  about  ten  c.c,  of  water.  This  animal  had 
previously  received  .3  gram  by  the  oesophageal  tube,  but,  in  spite  of 
well-developed  symptoms  of  poisoning,  had  recovered.  1.30,  marked 
dyspncen.  with  vomiting.  1.40,  tremors  and  slight  spasm.  1.57,  saliva- 
tion and  slight  spasm.  2  o'clock,  clonic  spasms  of  the  extremities, 
tetanic  spasm  of  the  masseters,  thick  mucus  expelled  from  the  mouth. 
2.05,  marked  dyspncea,  animal  lying  upon  its  side.  2.10,  recurring 
clonic  spasm  ;  animal  does  not  respond  to  calls  or  to  strong  irritation. 
2.15,  death,  muscles  stiff.  Post-mortem  as  above.  No  methasmo- 
globin  in  blood. 

Exp.  7. — To  the  animal  that  had  been  employed  in  experiment  No. 
3  the  following  doses  of  dinitrocresol  (same  sample  as  above)  were 
administered  subcutaneously.  At  10.40  A.  M,,  o.i  gram.  At  12.15, 
animal  was  somewhat  weak,  then  improved.  12.20,  o.i  gram  admin- 
istered ;  animal  became  weak.  At  2  o'clock,  .2  gram.  At  2.30,  active 
expiration,  abdominal  breathing.  At  2.45,  dyspnoea,  responds  to 
call  by  wagging  tail;  slight  cramps,  and  subsequent  complete 
recovery. 

Exp.  8. — Dog  weighing  3420  grams,  received,  subcutaneously,  at 
10.30,  on  January  27,  1888,  0.1  gram  of  the  Bremerhaven  sample  dis- 
solved in  ten  c.c.  of  water.  11.06,  vomiting.  11.27,  renewed  vomiting. 
12  o'clock,  vomiting.  12.50,  0.2  gram  subcutaneously.  12.55,  vomiting 
of  yellow  masses,  i.io,  spasmodic  retching,  yellow  masses  expelled. 
1. 1 1,  weak  clonic  seizure.  1.16,  animal  lay  upon  its  side;  strong 
clonic  seizure  ;  tetanus  of  the  masseter  muscles,  mouth  wide  open. 
1. 18,  very  marked  dyspnoea,  continuous  spasm.  1,20,  death,  muscles 
stiff.     Post-mortem  showed  the  usual  appearances. 

Exp.  9. — Dog  weighing  5690  grams  received,  subcutaneously,  at 
10.40  A.  M.,  O.I  gram  of  saffron-substitute,  made  by  Mittenzwey, 
dissolved  in  twenty-five  c.c.  of  lukewarm  water,  the  proportion 
being  0.17  gram  per  kilo  of  body  weight.  At  10.51,  breathing  very 
rapid.     11.35,  animal  was  sitting  quietly.     11.50,  apparently  normal. 


78 


THE    COAL-TAR   COLORS. 


12.15,  0-2  gram  subcutaneously,  12.25,  respirations  accelerated. 
12.26  to  12.30,  vomiting  followed  by  tremors.  12.31,  vomiting  of  a 
tough  yellow  mucus.  12.32,  weak  clonic  seizure.  12.35,  strong  clonic 
seizure,  spasm  of  the  masseters,  white  foam  issuing  from  the  mouth. 
12.36,  strong  clonic  spasm  ;  pupils  sensitive.  12.40,  the  seizures  are 
not  relieved  by  irritation  of  sensitive  surfaces.  Very  rapid  breathing  ; 
animal  lay  upon  its  side.  Successive  clonic  seizures  occurred  at  the 
following  periods  :  12.05,  12.49,  ^2.52,  12.55,  r,  1.02,  1.05,  1.08,  1.15, 
1.26,  respirations  108  ;  1.22,  respirations  120;  1.38,  respirations  148  ; 
1.39,  respirations  180;  1.45,  respirations  120;  1.50,  breathing  slower, 
animal  lay  upon  its  side  with  eyes  open.  1.52,  spontaneous  move- 
ments. 2,  breathing  much  quicker;  2.10,  respirations  90.  2.25, 
spontaneous  movements  of  head.  2.30,  wags  its  tail  somewhat.  2.45, 
animal  recovered,  but  still  lay  on  its  side.  Following  day  alive  and 
apparently  well. 

EXPERIMENTS  ON  DOGS. 


Weight 

Propor- 

Method 

No. 

OF 

Animal. 

Dose. 

tion  TO 
Kilo- 
gram. 

Sam- 
ple. 

Duration  of 
Case. 

Remarks. 

OF 

Adminis- 
tration. 

I 

6,230 

1-5 

0.2 

a 

.    .     .     . 

Recovery. 

By  stom- 
ach. 

2 

5,500 

0-3 

0.055 

a 

.... 

(( 

(( 

0 

5'5oo 

0.3 

0.055 

a 

40  minutes. 

.    .    . 

(( 

4 

6,230 

0.3 

0.048 

a 

.... 

Recovery. 

(( 

5 

14,500 

0.7 

0.05 

a 

.... 

a 

Hypo- 

6 

6,230 

O.I 

0.016 

a 

75  minutes. 

dermi- 
cally. 

7a 

14,500 

O.I 

0.007 

a 

.... 

Recovery. 

7b 

« 

O.I 

0.007 

a 

.... 

« 

7c 

.    .    . 

0.2 

0.014 

a 

.    .    .    . 

a 

8 

3.420 

0.1 

0.029 

f 

170  minutes. 

.     .     . 

9a 

5.690 

O.I 

0.017 

e 

.... 

Recovery. 

9I) 

.  .   . 

0.2 

0.035 

e 

.... 

<( 

The  preceding  table  needs  but  little  explanation.     It  is  clearly 
apparent  that  the  animals  which  received  .05  gram  of  dinitrocresol 


NITRO-COLORS.  79 

salt  by  the  stomach,  in  Experiments  2  to  5,  did  not  die  in  all 
cases.  These  phenomena  will,  however,  be  easily  understood 
when  we  recollect  that  the  dosage  of  such  a  substance  is  deceptive 
in  view  of  the  frequent  vomitings  which  it  produces.  It  depends 
upon  accident,  not  entirely  under  the  control  of  the  experi- 
menter, whether  much  or  little,  or  even  none,  of  the  material 
administered  reaches  the  system  proper.  This  is  especially  true 
of  Exp.  I.  With  the  subcutaneous  administration  the  con- 
ditions were  as  follows  : — Exps.  6  and  7  were  comparable,  since 
the  same  preparation  was  employed.  The  animal  lived  that 
received  seven  milligrams  per  kilogram  of  body  weight  (Exps. 
7  a  and  7  b.).  Sixteen  milligrams  per  kilogram  killed  in  Exp. 
6.  Fourteen  milligrams  per  kilogram  was  not  fatal  in  the  case 
of  the  very  large  dog  in  Exp.  7  c.  In  Exp.  8  twenty-nine  milli- 
grams were  required  for  a  fatal  effect,  therefore  it  took  almost 
double  the  dose  that  was  sufficient  in  Exp.  6.  The  Bremerhaven 
preparation  employed  in  Exp.  6  contained,  as  was  ascertained, 
about  thirty-three  per  cent,  of  ammonium  chloride  while  the  ma- 
terial used  in  the  other  experiments,  obtained  from  the  Polytech- 
nic College  laboratory,  was  nearly  pure  potassium  dinitrocresol. 
The  animal  used  in  Exp.  9,  to  which  the  Mittenzwey  preparation 
was  given,  was  also  dangerously  affected,  as  is  shown  in  the 
notes  of  this  experiment.  Dogs  upon  which  the  experiments 
were  made  exhibited  the  following  characteristic  toxic  symp- 
toms. Whether  the  color  was  introduced  directly  into  the 
stomach  or  beneath  the  skin,  nausea  and  vomiting  invariably 
ushered  in  the  poisoning.  Active  inspiratory  movements ;  and 
dyspncea  succeeded  these,  then  followed  excessive  salivation  and 
characteristic  trembling  of  the  entire  frame.  At  this  period  the 
animal  generally  lay  helpless  on  one  side.  The  first  convulsive 
seizure  then  showed  itself  and  was  especially  exhibited  by  pawing 
the  air-  A  second  and  even  a  third  convulsive  seizure  followed, 
and  in  the  latter  the  animal  generally  succumbed.  The  muscles 
became  rigid  a  few  moments  after  death.  In  some  cases  the 
animal  recovered  after  one  or  two  hours'  suffering. 

The  toxic  dose  for  dogs  is  from   seven  to  ten  milligrams  per 


8o 


THE    COAL-TAR    COLORS. 


kilogram  of  body  weight  in  hypodermic  administration.  The  fatal 
dose  is  sixteen  milligrams  with  a  perfectly  pure  potassium  dinitro- 
cresol :  twenty-nine  milligrams  per  kilo  of  body  weight  of 
the  commercial  preparation,  which  contains  about  thirty  per 
cent  of  ammonium  chloride.  The  following  formulae  show 
that  the  saffron-substitute  is  related  to  phenol  and  picric  acid  :  — 

CeH.HO  Phenol.  CgH^CHgHO  Cresol. 

C6H.HO(N02)3  picric  acid.  C6H2HOCH3(N02)2  dinitrocresol. 

The  symptoms  of  poisoning  by  dinitrocresol  agree  in  several 
material  points  with  those  of  phenol,  as  E.  Salkowsky  has  shown 
in  the  case  of  rabbits  and  J.  Munk  in  the  case  of  dogs.  Indeed, 
poisoning  by  saffron-substitute  could  almost  be  designated  as 
phenol  poisoning,  except  that  the  dinitrocresol  is  the  more  pois- 
onous, as  the  following  comparison  indicates  : — 


Material. 

Method  of 
Administration. 

Lethal  Dose  per 
Kilogram. 

• 

Rabbit.              Dog. 

Phenol, 

Stomach. 
Subcutaneously. 

0.45               0.5 
0.25        j       0.029 

0.25      [      o.or6 

Dinitrocresol,  commercial,     . 
"           pure,     .... 

In  this  table  doses  administered  by  the  mouth  are  compared 
with  those  administered  subcutaneously.  This  has  been  done 
because  saffron-substitute  administered  by  the  mouth  causes  vom- 
iting, and  the  doses  cannot  be  accurately  estimated.  Moreover, 
the  lethal  dose  of  phenol  administered  subcutaneously  to  dogs 
seems  not  to  have  been  determined.  If  we  assume  that  phenol 
has  fifty  per  cent,  more  activity  when  acting  through  the  subcu- 
taneous cellular  tissue,  which  is  certainly  more  than  the  neces- 
sary allowance,  dinitrocresol  will  still  be  materially  more  active. 
A  characteristic  difference  between  dinitrocresol  and  phenol 
poisoning  is  the  vomiting  which  the  former  substance  develops.* 


*  Picric  acid  also  produces  vomiting. 


NITRO-COLORS.  Si 

The  experiments  given  indicate  the  poisonous  nature  of  dini- 
trocresol.  They  justify  the  hope  that  the  State  may  restrict  the 
sale  of  so  dangerous  a  material  and  prohibit  its  employment  for 
the  coloring  of  food  and  drink.  This  opinion  will  be  still  more 
strengthened  by  the  notes  of  a  case  of  fatal  poisoning  by  saffron- 
substitute,  for  information  of  which  I  am  indebted  to  the  kind- 
ness of  Dr.  With,  Police  Surgeon  of  Bremerhaven. 

On  August  9,  1887,  Mrs.  J.,  a  married  woman  of  Bremer- 
haven, obtained  fifteen  pfennings'  worth  of  "  safran  "  with  the 
intention  of  employing  it  as  an  abortifacient.  She  took  the 
red  powder  at  eight  o'clock  in  the  morning,  was  seized  with 
vomiting,  and  died  at  one  o'clock  of  the  same  day.  A  post- 
mortem examination  was  made  on  the  next  day  and  exhibited 
the  following  appearances :  The  abdomen,  conjunctiva,  and 
mucous  membrane  of  the  mouth  were  pale  yellow ;  no  corrosion 
was  observed  in  the  mouth.  The  heart  contained  a  dark  yellow 
semm.  There  was  no  liquid  in  the  pleural  cavity.  The  bronchi 
and  lungs  contained  a  yellowish-green  liquid.  Nothing  abnor- 
mal was  observed  in  the  intestines.  The  mucous  membrane  of 
the  stomach  was  covered  with  a  brownish-yellow  material,  and 
the  contents  of  the  stomach  on  being  diluted  with  water  exhib- 
ited, in  thin  layers,  an  intensely  yellow  color ;  in  thick  layers,  a 
brown-yellowish  red.  The  contents  of  the  bladder  had  the 
same  peculiar  yellow  color  as  the  skin.  No  bile  colors  were 
found  in  the  urine.  I  have  no  information  in  regard  to  the  con- 
dition of  the  uterus.  The  authorities  at  Bremerhaven  sent  me 
about  ten  grams  of  the  powder  remaining  from  that  which  the 
woman  had  taken,  which  I  subjected  to  a  toxicological  and 
chemical  investigation.*  I  have  already  given  a  report  of  the 
former  (see  p.  78).  In  order  to  present  a  synopsis  of  the  ac- 
tions of  these  substances,  I  placS  here  in  tabular  form  the  result 
of  the  investigations  of  the  Bremerhaven  preparation,  together 
with  those  of  the  commercial  article  from  Mittenzwey,  because, 

*I  am  also  under  obligations  to  Professor  Otto,  of  Brunswick,  and  Mr, 
Techner,  an  apothecary  in  Bremerhaven,  for  furnishing  me  small  specimens  of 
the  same  powder. 

7 


82 


THE    COAL-TAR   COLORS. 


as  will  appear  later,  the  two  preparations  were  found  to  be  iden- 
tical. 

COMPARISON  BETWEEN  EFFECTS  OF  SAMPLES  "  E  " 

AND  "F." 


No. 

Sam- 
ple. 

Animal. 

Method 

OF 

Adminis- 
tration. 

Weight  of 
Animal. 

Do 

Actual. 

SE. 

Per 
Kilo. 

Remarks. 

I 

2 

3 
4 
5 
6 

7 

8a 

8b 

f 
f 
f 
f 
e 
e 
f 
e 
e 

Rabbit. 
(< 

(( 

(( 

(( 

<( 

Dog. 

(( 

Stomach, 
<( 

<( 

Subcutan. 

Stomach. 

Subcutan. 
(( 

i6io 

1970 
1870 
1825 

1750 
1690 
3420 
5690 

0.4 
0.5 

0.45 
0.2 

0  42 

0.42 

O.IO 

O.IO 

0.20 

0.24 

0.25 

0.24 

0.109 

0.24 

0.25 

0.029 

0.017 

0.035 

Died  in  2  days. 
"       "   165  mins. 
»       «   135     " 

<(       ((      Mj      « 

"       "   140     " 
"      "   150     " 
u      «   150     " 
Recovery.. 

These  experiments  show  that  the  Bremerhaven  preparation  is 
capable  of  killing  rabbits  and  dogs  in  small  doses  whether  ad- 
ministered by  the  stomach  or  subcutaneously.  The  character- 
istic symptoms  to  which  the  animals  succumb  are  exhibited 
above. 

Chemical  Investigation. — The  Bremerhaven  preparation  was  a 
loose,  orange-red,  distinctly  crystalline  powder.  Heated  in  a 
test  tube,  it  was  decomposed  with  evolution  of  nitrous  vapors. 
Heated  on  platinum  foil,  it  decomposed  with  a  hissing  noise. 
On  treating  it  with  water  at  ordinary  temperature,  a  portion  of 
the  powder  dissolved  to  an  orange  solution,  another  portion 
remaining  undissolved  as  a  broWnish-black,  tar-like  mass.  The 
latter,  by  warming,  was  nearly  all  dissolved.  The  watery  solu- 
tion dyed  silk  and  wool  orange,  but  the  color  could  be  almost 
entirely  withdrawn  by  washing  with  hot  water.  The  aqueous 
solution  was  not  precipitated  by  ammonium  hydroxide.  The 
aramoniacal  copper  solution  produced,  after  twenty-four  hours' 


NITRO-COLORS.  S^ 

Standing,  a  minute  flocculent  precipitate.  Addition  of  dilute 
sulphuric  or  hydrochloric  acid  to  the  watery  solution  produced 
a  crystalline  precipitate.  This  was  recrystallized  several  times 
from  hot  water,  and  yellow  needles  were  obtained  having  a 
melting  point  of  79-80°.  Pure  dinitrocresol  salts  melt  at  84°; 
orthodinitrocresol,  at  86°.  The  crystals  contained  nitrogen, 
exploded  lightly  by  quick  heating,  and  dissolved  in  alcohol  and 
alkalies  to  an  orange  color.  It  was  clear  that  I  had  here  a  mix- 
ture of  para-  and  ortho-dinitrocresol.  A  more  complete  separa- 
tion and  ultimate  analysis  was  not  possible  by  reason  of  the 
scantiness  of  the  sample.  The  quantitative  analysis  of  the  ma- 
terials present  in  the  Bremerhaven  preparation  was  carried  out 
by  the  following  methods  :  — 

(a)  Two  grams  of  the  powder  were  dissolved  in  300  c.c.  of 
hot  water  mixed,  while  yet  warm,  with  dilute  sulphuric  acid  and 
allowed  to  stand  for  twenty-four  hours.  The  precipitate  was 
then  collected  on  a  tared  filter,  washed  with  some  water,  dried 
in  vacuo,  and  weighed.  The  yellow  filtrate  was  then  shaken  with 
ether  until  decolorized  and  the  ether  evaporated  in  a  weighed 
dish;  The  residue  was  treated  in  vacuo  with  sulphuric  acid, 
weighed,  and  the  weight  calculated  with  that  upon  the  filter  as 
dinitrocresol.  The  watery  filtrate,  now  practically  colorless, 
was  freed  from  ether,  made  up  to  one-half  of  a  litre.  The  solu- 
tion contained  potassium,  ammonium,  and  chlorine.  The 
chlorine  was  determined  by  titration  with  silver  nitrate  and 
calculated  to  ammonium  chloride,  while  the  potassium  was  cal- 
culated to  potassium  dinitrocresol  from  the  weight  of  the  dini- 
trocresol obtained  as  above.  I  obtained  from  two  grams  of 
dinitrocresol  by  precipitation,  0.7065,  from  the  ether  extract, 
0.33;  total,  1.0365;  hence,  51.8  per  cent,  of  dinitrocresol. 
Chlorine  by  titration,  .4524,  equivalent  to  .67  of  ammonium 
chloride,  hence  33.5  per  cent. 

(^)  In  the  second  analysis,  two  grams  of  the  powder  were 
dissolved  in  300  c.c.  of  water  and  excess  of  dilute  sulphuric 
acid,  and  the  liquid  rapidly  extracted  with  ether  until  colorless. 
The  residue  from  the  ethereal  extract  was  dried  in  vacuo  from 


84  THE    COAL-TAR   COLORS. 

sulphuric  acid  and  weighed.  There  was  obtained  dinitrocresol. 
.984  gram,  49,2  per  cent.  The  mean  of  the  two  experiments 
would,  therefore,  give  50.5  per  cent,  of  dinitrocresol,  which 
corresponds  to  60  per  cent,  of  potassium  dinitrocresol.  Adding 
to  this  33.5  per  cent,  of  ammonium  chloride,  the  difference 
between  this  amount  and  100  (6.5  per  cent.)  may  be  reckoned 
as  moisture  and  loss.  By  comparing  the  Bremerhaven  powder 
with  the  commercial  saffron-substitute  in  my  collection,  it  was 
shown  that  the  preparation  from  Mittenzwey  agreed  com- 
pletely in  its  color  as  well  as  its  chemical  properties  with 
the  specimen  from  the  Bremerhaven  case.  This  chemical 
identity  was  completely  confirmed  by  the  similarity  of  the 
toxicological  action  of  the  two  preparations.  This  point  is 
fully  presented  above.  Furthermore,  a  judicial  inquiry  dis- 
closed the  fact  that  the  Bremerhaven  preparation  had  been 
obtained  from  Mittenzwey.  The  toxicological  and  chemical 
investigations  which  I  have  stated  demonstrate  with  certainty 
that  the  Bremerhaven  woman  died  of  poisoning  by  saffron- 
substitute.  With  the  intention  of  bringing  about  an  abortion  by 
using  saffron,  she  had  taken,  in  the  place  of  the  well-known  drug 
(^Crocus  sativus),  the  artificial  color,  saffron-substitute.  The 
material  had  cost  15  pfennings.  Since  the  dye-stuff  is  sold 
by  the  manufacturer  for  23  marks  per  kilo,  and  the  retailer 
will  expect  in  such  small  sales  at  least  50  per  cent,  profit,  the 
woman  obtained  about  4.5  grams  for  15  pfennings.  Assuming 
that  she  weighed  75  kilo,  the  fatal  dose  of  the  Mittenzwey 
preparation  may  be  reckoned  at  .06  gram  per  kilo  of  body- 
weight.  It  must  here  be  noted  that  the  Bremerhaven  prepara- 
tion could  not  have  contained  appreciable  amounts  of  other 
nitro-compounds,  especially  picric  acid. 

I  have  satisfied  myself  that  the  ordinary  and  commercial 
samples  of  nitro-colors,  with  the  exception  mentioned,  yield, 
even  when  largely  diluted,  a  precipitate  with  ammoniacal  copper 
sulphate.  Even  brilliant  yellow,  which  forms  a  relatively  easily 
soluble  copper  compound,  could  not  have  been  present,  since 
it  is  precipitated  by  sodium  hydroxide  and  would  have  given  a 


NITRO-COLORS.  85 

characteristic  reaction  with  ferric  chloride.  For  human  beings, 
therefore,  as  the  Bremerhaven  affair  shows,  dinitrocresol  is  highly 
poisonous  even  in  small  amounts,  and  the  sale  of  such  a  substance 
should  be  restricted  by  legal  provision. 

Martius'  Yellow. 

This  color  is  named  after  its  discoverer,  Dr.  C.  A.  Martius,  of 
Berlin.  It  is  also  known  as  naphthol  yellow,  naphthalene  yellow, 
Manchester  yellow,  saffron  yellow,  and  golden  yellow.  It  is 
dinitro-a-naphthol.     The  structural  formula  is  as  follows:  — 

OH 

^N0. 


Several  methods  are  available  for  its  preparation. 

1.  a-amidonaphthalene  is  treated  with  hydrochloric  acid  and 
sodium  nitrite  (diazotized),  and  the  resulting  diazonaphthalene 
chloride  is  boiled  with  nitric  acid,  when  the  color  separates  in 
fine  yellow  crystals.     The  reactions  are  as  follows  : — 

C10H7NH2  +  2HCI  +  NaNO.,  =  CioH^N3=N— CI  +  NaCl  +  aH^O 
CioH^— X=X— CI  +  2HNO3  =  CioH7HO(N02)2  +  N2  +  HCl  +  2H2O. 

2.  a-naphthol  is  treated  with  sulphuric  acid,  by  which  a- 
naphtholsulphonic  acid  is  produced,  and  this,  on  being  heated 
with  dilute  nitric  aCid,  yields  the  color. 

CioH^HO  +  H2SO,  =  CjoHgHOHSOg  +  H2O 
C10H-HOHSO3  +  2HNO3  =  C,oH5HO(N02)2  +  HgSO^  +  H2O. 

In  commerce,  calcium,  sodium,  and,  more  rarely,  ammonium 
salts  of  the  preparation  are  seen.  The  first  mentioned  is  a  yellow- 
ish orange  powder  difficultly  soluble  in  water.  The  sodium  salt 
forms  reddish  crystals,  tolerably  soluble.  These  substances  are 
usually  reduced  by  admixture  with  dextrine. 

Typical  Reactio?is. — The  powder  dissolves  in  sulphuric  acid  to 
a  reddish-yellow  color.  The  solution  becomes  turbid  on  dilu- 
/tion.     Ether  added    to  this  liquid  becomes  only  very   slightly 


86  THE    COAL-TAR    COLORS. 

tinged  with  yellow.  If  the  ether  be  removed  carefully  and 
treated  with  sodium  hydroxide  or  sodium  carbonate,  it  becomes 
decidedly  yellow.  The  solution  in  water,  rendered  alkaline, 
becomes  brown-yellow.  After  long  boiling  with  potassium 
cyanide,  the  aqueous  solution  of  the  dye  takes  on  a  brown  color 
and  then  becomes  intensely  dark  brown  (naphthylpurpuric  acid). 
This  reaction  with  potassium  cyanide  takes  place,  as  it  appears, 
with  all  nitro-colors.  Heat  causes  it  to  explode  slightly.  The 
watery  solution  becomes  turbid  by  the  addition  of  a  small  amount 
of  acid  (distinction  from  naphthol  yellow  S,  picric  acid,  and 
aurantia,  (see  also  brilliant  yellow).  The  watery  solution  gives 
with  sodium  hydroxide  after  some  delay  a  fiocculent  red  precipi- 
tate. (Compare  brilliant  yellow.)  (Picric  acid,  dinitrocresol, 
naphthol  yellow  S,  and  aurantia  are  not  precipitated  by  sodium 
hydroxide.)  With  ammoniacal  copper  solution  a  crystalline 
precipitate  occurs,  even  when  very  much  diluted.  The  copper 
compound  is  soluble  in  hot  water,  and  with  strong  hydrochloric 
acid  gives  a  precipitate  of  free  dinitronaphthol  which  may  be 
tested  with  the  procedure  with  ether  given  above. 

Reduction  by  means  of  hydrochloric  acid  solution  of  stannous 
chloride  produces,  in  the  presence  of  ammonium  hydroxide,  an 
orange-red  liquid  ;  in  presence  of  ferric  chloride,  a  fuchsin-red 
solution.  Ferric  chloride  produces  a  yellowish  precipitate  which, 
together  with  the  liquid,  turns  red  on  boiling. 

Since  Martins'  yellow  rubs  off  easily  and  is  also  very  volatile 
on  heating,  it  is  now  but  little  employed  for  dyeing  wool  or  silk. 
According  to  G.  Schultz,  it  is  employed  in  printing  on  textiles. 
It  is  used  for  the  coloring  of  food  (maccaroni)  in  France  and 
Italy.*  Concerning  the  action  of  Martins'  yellow  upon  the 
animal  organism,  reliable  investigations  were  made  by  Caze- 
neuve  and  Lepine.     These  observers  employed  the  sodium  salt. 

A  dog  weighing  7  kilos  received  daily  .05  gram  (probably  per  kilo) 
of  the  powder  introduced  into  the  throat.     On  the  second  day  oc- 


•  *  According  to  a  report  made  by  Dr.  Erhardt,  Sanitary  Officer,  to  Count  Solms, 
German  Minister  to  Italy,  and  kindly  placed  at  my  disposal. 


NITRO-COLORS.  87 

curred  diarrhoea  and  vomiting  of  yellow  masses.  The  animal  re- 
fused nourishment,  except  milk.  On  the  fourth  day  dyspnoea  and  a 
temperature  of  41°  was  noted.  The  symptoms  continued  to  increase 
in  intensity  and  the  respirations  became  croupy.  Temperature  42°, 
appetite  gone.  Urine  contained  the  color  and  was  albuminous. 
Animal  died  on  this  day.  Post  mortem  showed  the  intestines  col- 
ored yellow.  In  a  second  experiment  a  dog  weighing  22  kilos  re- 
ceived .4  gram  (probably  per  kilo)  suspended  in  syrup.  On  the  fol- 
lowing day  .5  gram  was  administered.  The  symptoms  were  as  in  the 
first  case.  The  animal  was  killed.  Post-mortem  showed  no  discolor- 
ation of  the  intestines,  but  an  extensive  congestion  of  the  same. 

Further  investigations  were  carried  out  upon  dogs  weighing 
from  10  to  25  kilos,  to  which  proportions  of  the  color  varying 
from  .3  to  .6  per  kilo  of  the  body  weight  dissolved  in  .7  per 
cent,  solution  of  sodium  chloride  were  injected  into  the  femoral 
vein.  The  temperature  rose  to  44°.  Marked  dyspnoea  was  de- 
veloped. Death  resulted  in  45  to  minutes  to  i^  hours.  Doses 
of  .1  gram  per  kilo  injected  into  the  blood  were  followed  by  the 
same  symptoms,  but  the  animal  recovered.  I  gave  to  two  rabbits, 
weighing  1797  and  2100  grams  respectively,  .55  gram  of  the 
ammonium  salt  and  1  gram  of  the  potassium  salt  respectively. 
No  symptoms  of  poisoning  appeared  in  these  cases.  The  fol- 
lowing investigations  were  undertaken  with  dogs.  The  easily 
soluble  sodium  salt  was  fed  to  the  animal.  The  material  was  in 
yellowish-red  needle-shaped  crystals,  and  was  manufactured  from 
the  calcium  compound  obtained  from  Kuhnheim  &  Co.,  in 
Berlin. 

Exp.  I. — Dog  weighing  6850  grams  received  by  the  oesophageal 
tube  on  March  10,  1888,  one  o'clock,  .5  gram  Martius'  yellow  sodium 
salt  suspended  in  about  25  c.c.  of  water.  i.io,  strong  efforts  at 
vomiting.  At  6  o'clock  vomiting  occurred.  March  nth,  10  o'clock 
A.  M.,  animal  very  weak,  rectal  temperature  40.8°,  vomiting  and 
diarrhoea,  urine  rather  darker  than  the  salt  administered  and  contain- 
ing traces  of  albumin.  Strongly  acidulated  with  sulphuric  acid,  it 
yielded  a  weak,  yellow-colored  extract  ether.  Sodium  hydroxide 
solution  added  to  the  ether  colors  it  a  pure  yellow  and  becomes  itself 
icolored.    Addition  of  hydrochloric  or  sulphuric  acid  renders  the  urine 


88  THE    COAI-TAR    COLORS. 

turbid  by  separation  of  free  dinitronaphthol.  No  injection  was  made 
at  this  date.  March  12th,  one  o'clock,  .5  gram  was  given  by  the 
oesophageal  tube,  i  .10,  vomiting  ;  animal  was  then  lively  with  normal 
breathing.  March  13th,  diarrhoea,  but  lively  and  ate  at  midday; 
albumin  in  urine.  March  14th,  11  o'clock,  i  gram  by  the  oesophageal 
tube.  Efforts  at  vomiting,  but  up  to  three  o'clock  in  the  afternoon  no 
actual  vomiting  occurred.  March  1 5th,  animal  was  found  dead  in  its 
cage.     Post-mortem  was  accidentally  omitted. 

Exp.  2. — Dog  weighing  5700  grams  received,  March  22d,  o.i  gram 
by  the  oesophageal  tube.  March  28th,  five  Hving  pups  were  born. 
March  24th  to  29th,  animal  and  progeny  remained  in  good  health. 

Experiment  No.  i  indicates  the  poisonous  quality  of  Martius' 
yellow  when  administered  by  the  stomach,  since  any  other  cause 
of  death  seems  to  be  excluded.  The  following  experiments,  in 
which  the  color  was  administered  subcutaneously,  are  more 
positive  in  their  indications. 

Exp.  J. — Dog  weighing  5800  grams  received,  April  30th,  I(?a.  m., 
.1  gram  dissolved  in  about  25  c.c.  of  water  injected  subcutaneously 
at  various  points  on  the  back.  The  animal  remained  lively,  but  in 
the  afternoon  had  diarrhoea.  On  May  ist  and  2d  .1  gram  was 
administered  in  the  same  manner.  Diarrhoea  continued,  urine  con- 
tained much  albumin ;  addition  of  acid  caused  a  precipitate  of 
dinitronaphthol.  Ether  shaken  with  the  liquid  became  feebly  yellow. 
Addition  of  alkali  to  the  ether  extract  caused  it  and  the  alkaline 
solution  to  become  deep  yellow.  The  feebly  acidified  urine  dyed 
wool  a  yellowish  brown.  May  3d,  .1  gram  subcutaneously.  May 
4th,  .15  gram  subcutaneously.  Urine  contained  albumin.  Dyeing 
of  wool  took  place  very  satisfactorily.  This  experiment  shows  that 
small  doses  of  Martius'  yellow  administered  subcutaneously  produced 
albuminuria. 

Exp.  4. — Dog  nveighing  8800  grams  received,  April  30th,  .1  gram 
subcutaneously.  May  ist  and  2d,  the  same.  Great  thirst  was 
exhibited.  May  3d,  same  dose  administered.  Thirst  and  poor  appe- 
tite. May  4th,  ID  A.  M.,  0.2  gram  subcutaneously.  Urine  was  dark 
brown,  contained  albumin,  and  died  wool  yellow.  At  four  o'clock, 
six  hours  after  the  injection,  strong  dyspnoea  and  great  thirst.  At 
seven  o'clock  the  animal  was  quite  apathetic,  with  marked  dyspnoea. 
Died  during  the  night.     Post-mortem  showed  venous  congestion  of 


NITRO- COLORS.  89 

the  liver,  spleen,  kidneys,  and  lungs,  incipient  pneumonia,  intestines 
and  skin  not  tinged. 

This  experiment  demonstrates  beyond  cavil  that  the  poisoning 
was  the  sole  cause  of  death,  since  the  operation  of  subcutaneous 
administration  cannot  be  reckoned  as  contributing  to  the  results. 
The  animal  took  in  the  course  of  five  days  nearly  .6  gram  of  the 
sodium  salt  of  Martius'  yellow;  therefore,  nearly  .07  gram  per 
kilo  of  the  body  weight. 

Poisoning  by  this  color  presents  the  following  symptoms : 
Administered  by  the  stomach  it  causes  vomiting  ;  animals  suffer 
from  intense  thirst,  high  fever,  with  marked  dyspnoea.  After  the 
first  dose,  albuminuria  appears.  Generally,  the  animal  succumbs, 
and,  as  it  seems,  by  asphyxia.  If  the  substance  be  introduced 
directly  into  the  blood  (Cazaneuve  and  Lepine)  or  injected 
subcutaneously,  similar  symptoms,  with  the  exception  of  vomit- 
ing, are  noted. 

Martius'  yellow,  therefore,  belongs  to  the  injurious  colors.  As 
a  coloring  matter  for  food  and  drink  its  use  should  be  wholly 
prohibited.  For  dyeing  materials  that  may  come  in  contact 
with  the  skin,  its  use  is  also  inadvisable,  since  an  abrasion  of 
the  skin,  even  if  superficial,  may  permit  an  injurious  action  of 
the  poison.  The  experiments  in  which  the  animals  either 
sickened  or  died  by  introduction  of  the  Martius'  yellow  into 
the  blood  or  skin  demonstrates  this  point.  The  color  intro- 
duced with  the  food  is,  in  part,  at  least,  excreted  in  the  urine 
unchanged.  The  wool  dyed  by  the  urine  showed  a  somewhat 
darker  tint  than  that  obtained  from  the  pure  color,  doubtless  due 
to  the  action  of  coloring  matters  proper  of  the  urine. 

Naphthol  Yellow  S. 
This  color,  known  also  as  acid  yellow  S,  fast  yellow,  aniline 
yellow,  succinine,  saffron  yellow,  citron ine,  new  yellow,  and 
solid  yellow,  is  calcium,  sodium,  or  ammonium  dinitro-a-naph- 
thol-sulphonate.  CioH^OCNO.O.NaSOs.  It  may,  therefore,  be 
regarded  as  a  sulphonated  Martius'  yellow.  The  production  of 
naphthol  yellow  S  is  as  follows :  The  action  of  fuming  sulphuric 
8 


90  THE    COAL-TAR   COLORS. 

acid  upon  r/-amidonaphthalene  produces  a-amidonaphthalenetri- 
sulphonic  acid.  NH2C,oH4(HS03)3.  By  boiling  this  with  nitrous 
acid  (diazotizing)  a-naphtholtrisulphonic  acid,  CioH4HO(HS03)3, 
is  produced,  and,  by  heating  this  with  nitric  acid,  dinitro- 
a-naphtholsulphonic  acid,  CioH4HO(NOa)2HS03,  is  formed, 
a-naphthol  can  also  be  converted  directly  into  the  trisulphonic 
acid  by  the  action  of  fuming  sulphuric  acid  and  by  suitable 
treatment  of  this  with  nitric  acid. 

The  commercial  form,  which  is  usually  the  sodium  salt,  is  an 
orange  yellow  powder  easily  soluble  in  water.  It  is  commonly 
sold  mixed  with  dextrin  or  some  similar  diluting  agent. 

Typical  Reactions. — The  powder  dissolves  in  concentrated 
sulphuric  acid  with  greenish-yellow  color,  and  the  solution,  on 
dilution  with  water,  remains  clear.  (Distinction  from  Martius' 
yellow  and  aurantia.)  Ether  shaken  with  this  solution  remains 
colorless,  even  when  an  alkali  is  added  (compare  Martius' 
yellow),  because  the  color  acid  is  insoluble  in  ether.  I^  this 
means,  an  admixture  of  Martius'  yellow,  which,  by  reason  of  its 
lower  cost,  is  occasionally  substituted  for  naphthol  yellow  S,  may 
be  detected.  The  aqueous  solution  is  not  precipitated  by  hydro- 
chloric acid  (distinction  from  dinitrocresol,  Martius'  yellow, 
brilliant  yellow,  and  aurantia),  and  gives  no  precipitate  with 
sodium  hydroxide  (distinction  from  Martius'  yellow  and  brilliant 
yellow).  Potassium  cyanide  produces,  as  with  all  other  nitro- 
colors,  the  iso-purpuric  acid  color.  The  aqueous  solution  is  pre- 
cipitated, even  when  very  highly  diluted,  by  ammoniacal  copper 
solution.  The  solution  of  the  crystalline  precipitate  in  hot  water 
remains  clear  upon  addition  of  strong  hydrochloric  acid,  and 
yields  nothing  to  ether.  Hydrochloric  acid  solution  of  stannous 
chloride  produces,  on  addition  of  ammonium  hydroxide,  an 
orange  color  ;  on  addition  of  ferric  chloride,  a  red  color.  Ferric 
chloride  produces  a  Burgundy  red  precipitate,  which,  in  part, 
dissolves  on  heating  and  reappears  on  cooling. 

The  color  is  used  as  a  substitute  for  picric  acid  in  the  dyeing 
and  printing  of  wool  and  silk,  and  also  for  the  coloring  of  arti- 
cles of  food. 


NITRO-COLORS.  9 1 

Cazeneiive  and  Lepine  gave  a  dog,  weighing  15,000  grams,  .5 
gram  of  naphthol  yellow  S,  daily  for  fourteen  days ;  then,  for 
ten  successive  days,  2  grams  daily,  and  4  grams  daily  for  ten 
more  days.  The  animal  gave  birth  to  nine  pups,  of  which 
eight  lived.  No  disturbance  was  noticed  in  the  animal  and  the 
urine  was  free  from  albumin.  Occasionally  the  coloring  matter 
was  directly  injected  into  the  blood.  Symptoms  of  poisoning 
were  not  manifested.  With  human  beings,  2-4  grams  of  the 
color  per  day  produced  colic  and  diarrhoea. 

The  above-mentioned  authors  regard  the  color  as  non -poison- 
ous and  slightly  purgative.  It  is  to  be  noticed,  however,  that 
Cazeneuve  and  Lepine  state  that  the  naphthol  yellow  used 
(Jaune  NS.)  was  difficultly  soluble,  so  that  they,  probably, 
experimented  with  another  substance.  My  own  investigations 
were  made  on  dogs,  with  a  preparation  for  which  I  am  indebted 
to  the  kindness  of  Dr.  G.  Schultz,  of  the  Aniline  Manufacturing 
Co.,  of  Berlin.  It  was  purified  by  precipitation  and  recrystal- 
lization. 

Exp.  I. — Dog  weighing  480c  grams  received,  May  7th,  by  the  oesoph- 
ageal tube,  2  grams  dissolved  in  water.  May  8th,  appetite  good, 
quiet  breathing,  faeces  normal,  urine  neutral  and  free  from  albumin  ; 
wool  could  be  easily  colored  by  the  urine.  5.75  grams  were  admin- 
istered on  this  date  in  the  same  manner.  May  9th  and  loth,  no 
albumin  in  the  urine;  no  injection  made.  May  nth,  2  grams 
injected,  animal  normal,  doubtful  traces  of  albumin  in  the  urine. 
May  I2th,  2  grams  injected,  animal  normal ;  traces  of  albumm  in  the 
urine ;  faeces  normal. 

In  spite  of  the  undoubtedly  large  dosage  of  7.75  grams  in  six 
days,  1.6  grams  per  kilo  of  the  body  weight,  the  animal  exhibited 
no  symptoms  of  poisoning  and  only  extremely  limited  albumi- 
nuria, which  perhaps  existed  prior  to  the  experiment.  The 
following  experiment,  which  was  carried  out  with  a  dog  and  its 
3}^  weeks'  old  pup,  shows  that  even  by  the  subcutaneous  injec- 
tion of  the  naphthol  yellow  S,  no  symptoms  of  poisoning  are 
produced. 

Exp.  2. — Animal  weighing  5800  grams  received.  May  nth,  sub- 


92 


THE    COAL-TAR   COLORS. 


cutaneously,  .2  gram  in  about  32  c.c.  of  water.  Animal  remained  in 
good  spirits  and  had  good  appetite.  May  12th,  .2  gram  subcutane- 
ously.  May  13th  to  i6th,  animal  continued  lively;  appetite  not 
diminished;  nursed  its  young. 

Exp.  J. — Dog  3X  weeks  old,  weighing  1040  grams,  received,  May 
nth,  .1  gram  in  about  15  c.c.  of  water,  subcutaneously.  May  13th, 
.1  gram  in  same  manner.  Animal  was  lively,  and  continued  so  on 
the  following  day. 

This  experiment  shows  that  even  repeated  doses  of  .1  gram 
per  kilo,  of  body  weight  in  a  young  animal,  even  when  injected 
subcutaneously,  does  not  produce  any  perceptible  disturbances. 

The  harmlessness  of  naphthol  yellow  S  is  all  the  more  inter- 
esting in  view  of  the  fact  that  it  differs  from  the  markedly  poi- 
sonous Martins'  yellow,  merely  by  one  sulphonic  group  (HSO3), 
the  introduction  of  which  into  a  color  renders  it  soluble. 

Naturally,  one  would  suppose  that  a  soluble  color  would  prove 
more  poisonous  than  the  insoluble  color  from  which  it  was  pro- 
duced. Clearly,  therefore,  we  are  not  in  a  position  to  decide  as 
to  the  poisonous  or  non-poisonous  qualities  of  any  body  except 
from  actual  research,  even  when  we  correctly  know  the  consti- 
tutional formula.  That  poisonous  bodies  are  rendered  non- 
poisonous  by  the  introduction  of  a  sulphonic  group,  which 
attaches  itself  to  the  carbon  atom,  has  been  established  by  a 
series  of  investigations  (compare,  for  instance,  E.  Salkowsky's 
observations  on  phenol-sulphonic  acid,  Pfluger's  Archiv,  4,  92, 
187 1).  Further,  Cazeneuve  and  Lepine  found  that  colors  con- 
taining the  sulphonic  group  are  non-poisonous.  From  information 
kindly  communicated  to  me  verbally  by  E.  Salkowsky,  I  learn 
that  /-amidobenzenesulphonic  acid  is  not  poisonous.  The  in- 
vestigations of  Stolnikow  refer  to  the  influences  of  the  sulphonic 
group  attached  to  the  oxygen. 

Brilliant  Yellow  (Schoellkopf  ). 
I  am  indebted  to  the  kindness  of  G.  Schultz,  of  Berlin,  for  a 
sample  of  this  beautiful  color.     Brilliant  yellow  is,  apparently,  a 
dinitro-«-naphthol  sulphonic  acid,  isomeric  with  naphthol  yellow 


NITRO-COLORS.  93 

S.  The  commercial  form  is  a  sodium  salt,  which  is  a  yellow  powder 
rather  easily  soluble  in  water.  It  is  obtained  by  the  treatment 
of  naphtholdisulphonic  acid  with  nitric  acid,  according  to  the 
following  reaction  :  — 

C,oH,nO(HS03),  -f-  2IINO3  -  C,oH,HOIIS03(NO,).,  +  II,SO,  +  11,0. 

Typical  Reactions. — The  yellow-brown  solution  in  water  is 
rendered  a  paler  yellow  by  hydrochloric  acid,  but  not  precipi- 
tated. Ether,  shaken  with  this  solution,  becomes  pale  yellow. 
Sodium  hydroxide  produces  an  orange  red  crystalline  precipitate. 
Ferric  chloride  produces  a  dirty  greenish-yellow  color,  which,  by 
reflected  light,  is  opaque,  almost  black.  Before  the  appearance 
of  the  dark  color  the  solution  appears,  for  a  brief  period,  red- 
brown.  (Distinction  from  picric  acid,  naphthol  yellow  S, 
Martins'  yellow,  and  aurantia.)  Ammoniacal  copper  solution 
produces,  after  similar  treatment,  a  crystalline  precipitate.  With 
stannous  chloride  and  subsequent  addition  of  ammonium  hydrox- 
ide, or  ferric  chloride,  and  with  potassium  cyanide,  brilliant  yel- 
low behaves  like  Martins'  yellow. 

Exp.  7. — July  26th,  a  dog  weighing  5650  grams,  the  urine  of  which 
contained  a  trace  of  albumin,  received  by  means  of  the  oesophageal  tube 
3  grams  of  the  color  suspended  in  water.  July  27th,  the  animal  was 
in  good  spirits  and  ate  freely.  The  urine  was  colored  intensely 
orange-yellow.  The  urine,  slightly  acidulated  with  sulphuric  acid, 
dyed  wool  easily.  It  contained  brilliant  yellow  and  doubtful  traces 
of  albumin.  Treated  with  hydrochloric  acid,  it  yielded  to  ether  a  pale 
yellow  color.  Sodium  hydroxide  solution  decolorized  the  ether  almost 
entirely  and  was  itself  colored  yellow.  On  July  28th  the  animal  was  in 
good  spirits  and  appetite.  Urine  contained  a  small  amount  of  the  color. 
Three  grams  were  administered  by  the  oesophageal  tube,  dissolved 
in  a  little  peptone  to  avoid  corrosion  of  the  mucous  membrane  of  the 
stomach.  July  29th,  animal  quite  lively;  urine  almost  free  from 
albumin,  but  containing  much  coloring  matter  ;  dyeing  of  wool  was 
easily  done.  July  30th,  2^  grams  administered  in  the  same  manner, 
in  peptone.  The  urine  was  alkaline,  almost  free  from  albumin  ;  ani- 
mal in  good  spirits  and  appetite  good  ;  wool  easily  dyed  by  the  urine 
acidulated  with  sulphuric  acid.  July  31st,  3  grams  administered  as 
above.     August  5th,  animal  quite  normal  and  had  again  during  the 


94  THE    COAL-TAR   COLORS. 

course  of  the  experiment  i8o  grams.  The  brilliant  yellow  in  the  urine 
was  detected,  in  addition  to  the  dyeing  of  the  wool  in  the  acidulated 
liquor,  by  the  following  method.  The  liquid  was  rendered  strongly 
acid  with  hydrochloric  acid  and  shaken  with  ether.  The  ether  extract 
yielded  the  color  to  sodium  hydroxide  solution  and  in  the  latter  it  was 
detected  by  the  reactions  given  above. 

Exp.  2. — A  dog  weighing  11600  grams  was  selected  on  July  27th, 
and  the  urine  determined  to  be  free  from  albumin  and  sugar.  July 
28th,  0.2  gram  of  brilliant  yellow  suspended  in  ten  c.c.  of  water  were 
injected.  July  29th,  urine  intensely  orange  yellow  in  thin  layers,  in 
thick  layers  orange  red,  but  free  from  blood  and  albumin ;  the  animal 
was  lively  and  had  good  appetite.  July  30th,  0.3  gram  were  injected 
subcutaneously.  Animal's  condition  the  same,  but  urine  contained  a 
little  albumin.  July  31st,  animal  in  good  spirits  and  appetite. 
August  5th,  animal  lively,  urine  contained  very  little  albumin.  The 
dog  had  gained  about  300  grams  in  body  weight  since  the  beginning 
of  the  experiment.  Further  investigations  were  omitted  for  want  of 
material. 

Brilliant  yellow  is  not  poisonous,  even  in  large  doses,  when 
administered  by  the  stomach.  The  dog  which  had  received  com- 
paratively large  doses  subcutaneously  was,  at  the  end  of  the 
eighth  day  after  the  last  injection,  in  quite  good  spirits  and  appe- 
tite. The  albuminuria  was  very  slight.  In  this  color,  as  in 
naphthol  yellow  S,  we  observe  the  influence  of  the  sulphonic 
group  in  diminishing  the  poisonous  action. 

Aurantia. 
Aurantia,  or  imperial  yellow,  is  the  ammonium  or  sodium  salt 
of  hexanitrodiphenylamine : — 

NH,N[CeH2(N02)3]2. 

It  is  produced  by  the  action  of  nitric  acid  upon  diphenylamine 
or  methylphenylamine,  according  to  the  following  reaction  : — 

(CeH,),HN  +  6HNO3  =  HN[C6H,(NO,)3],  -|-  6H,0. 

The  commercial  article,  usually  the  ammonium  compound,  re- 
duced by  admixture  with  dextrin,  appears  in  brownish-red 
needles. 


NITRO-COLORS.  95 

Typical  Reactions. — The  powder  dissolves  in  concentrated  sul- 
phuric acid  to  a  weak  yellowish  color.  Addition  of  water  pro- 
duces a  flocculent  precipitate.  Solution  of  aurantia  produces 
with  strong  hydrochloric  acid,  a  precipitate  of  the  free  color  acid. 
Ether  dissolves  the  precipitate  and  acquires  a  yellow  color. 
Sodium  hydroxide  solution  decolorizes  the  ether  and  becomes 
itself  yellowish  brown,  almost  red.  Sodium  hydroxide  pro- 
duces no  precipitate.  (Distinction  from  Martins'  yellow  and 
brilliant  yellow.)  Ammoniacal  copper  solution  produces  a  cin- 
nabar red  precipitate.  This  gives,  with  fuming  hydrochloric 
acid,  a  precipitate  which  behaves  toward  ether  as  described 
above.  With  potassium  cyanide,  and  with  hydrochloric  acid 
solution  of  stannous  chloride,  with  the  subsequent  addition  of 
either  ammonium  hydroxide  or  ferric  chloride,  aurantia  behaves 
like  other  nitro-colors.  (Compare,  however,  picric  acid.) 
Ferric  chloride  produces  a  fawn-colored  precipitate. 

Aurantia  is  used  for  the  orange- dyeing  of  wool,  silk,  and 
leather.  Its  poisonousness  has  been  often  asserted  and  often 
denied.  According  to  Gnehm,  the  preparation  made  by  Binsch- 
edler  and  Busch  is  poisonous,  since  those  engaged  in  the  manu- 
facture of  the  color,  and  the  dyers  who  employ  it,  suffer  from 
vesicular  eruptions  and  marked  swelling  of  the  hands  and  arms. 
On  the  other  hand,  according  to  Martins,  the  preparation  of  the 
Aniline  Manufacturing  Company  of  Berlin  is  non-poisonous. 
E.  Salkowsky  and  Ziurek,  in  a  formal  opinion  based  upon  experi- 
ments made  on  rabbits,  with  a  very  much  reduced  preparation, 
agree  with  this  latter  view.  To  the  same  effect,  is  the  opinion 
expressed  by  the  Royal  Medical  Convocation  of  the  Rhine  Pro- 
vinces, April  18,  1880,  as  I  infer  from  a  decree  of  the  said  Con- 
vocation, dated  April  i8,  t88o.  It  appears  from  this  communica- 
tion that  the  opinion  refers  to  a  preparation  furnished  under  the 
name  of  aurantia,  or  imperial  yellow,  by  the  Aniline  Manufactur- 
ing Company  of  Berlin.  The  text  of  this  opinion  is,  unfortun- 
ately, not  accessible  to  me.  It  is  to  be  found  among  the  Acts 
of  the  Prussian  Educational  Bureau.  Perliaps  the  two  prepara- 
tions mentioned  above,  the  Berlin  and  Basle,  are  different,  or  the 


96  THE   COAL-TAR   COLORS. 

color  acts  differently  on  different  individuals.  Unfortunately, 
for  want  of  material,  I  could  not  conduct  the  investigations  on 
this  point. 

Other  Nitro-Colors. 

The  remaining  nitro-cplors,  mentioned  by  G.  Schultz  (Chem- 
istry of  Coal-tar,  second  edition,  4to,  p.  48,  etseq.),  flavaurin, 
phenyl  brown,  garnet  brown,  salicyl  yellow,  salicyl  orange,  pala- 
tin  orange,  and  heliocrysin,  are  no  longer  produced  on  a  com- 
mercial scale  and  are  not  important. 

Conclusions. — The  researches  which  are  on  record  concern- 
ing the  action  of  the  nitro-colors  upon  the  animal  organism 
point  to  the  following  conclusions.  Only  the  sulphonated  colors, 
naphthol  yellow  and  brilliant  yellow^  are  harmless  and  applicable 
to  the  coloring  of  food  and  drink.  Picric  acid,  dinitrocresol 
(saffron-substitute),  and  Martius'  yellow  are  poisonous  ;  aurantia, 
suspicious. 

AZO-COLORS.^^ 
Chemical  Considerations. 

Historical. — Peter  Griess  must  be  regarded  as  the  discoverer 
of  the  azo-colors  by  reason  of  his  thorough  investigations  of  the 
diazo-compounds,  which  are  the  sources  of  the  azo-bodies.  In 
1859  he  prepared  the  first  azo-color,  aniline  yellow  (amidoazo- 
benzene).  On  March  12,  1878,  he  took  out  the  first  German 
patent  (No.  3224,  class  22)  on  the  "  preparations  of  colors 
through  conjugate  combinations  of  diazophenols  with  phenols. " 
Shortly  after  Griess'  discovery,  Mene  (1861)  and  Simpson, 
Maule,  and  Nicholson  (1863)  obtained  aniline  yellow  by  the 
action  of  nitrous  acid  on  aniline.  They  introduced  the  color  into 
the  market  without  indicating  its  constitution.  Griess  and 
Martius  made  this  known  in  1866. 

The  second  azo-color  produced  artificially  and  introduced  into 
use  was  Bismarck  brown,  also  known  as  phenylene  brown  and  vesu- 

*  The  investigations  described  herewith  were  carried  out  in  the  Hygienic 
Institute  in  Berlin.  I  desire  to  express  my  sincere  thanks  to  Professor  Robert 
Koch  for  his  kind  interest  in  my  work. 


AZO-COI.ORS.  .  97 

vin,  discovered  by  C.  A.  Martins  in  1865.  In  1877  Caroand  Griess 
determined  this  to  be  triamidoazobenzene.  Ten  years  elapsed 
after  the  discovery  of  Bismarck  brown,  when  another  azo-color 
(chrysoidin)  was  prepared.  This  was  discovered  in  1875  ^Y 
H.  Caro,  and  in  the  early  part  of  1876  by  N.  O.  Witt,  being 
obtained  by  the  action  of  diazobenzene  chloride  on  metadiami- 
dobenzene.  Discoveries  began  to  follow  in  quick  succession. 
Roussin  prepared  orange  I  and  II,  in  1876  and  1877,  in  Poirrier's 
establishment.  Then  Griess  and  Witt  prepared  tropaeolin,  and 
since  1878  a  large  series  of  azo-colors  has  appeared,  principally 
prepared  in  German  factories,  and  especially  in  that  of  Meister, 
Lucius  &:  Briining,  at  Hoechst  o.  M.,  in  the  Baden  Aniline  and 
Soda  Manufactory,  and  by  the  Aniline  Manufacturing  Com- 
pany of  Berlin.  A  new  phase  in  the  production  began  in  1884, 
when  Paul  Bottiger  took  out  a  patent  (No.  28,753,  Class  22)  for 
the  "  preparation  of  azo-colors  by  the  combination  of  tetrazodi- 
phenyl  salts  with  a-  and  /5-amidonaphthalene,  or  their  mono-  and 
disuiphonic  acids.  Up  to  that  time  the  known  azo-colors  dyed 
wool  alone  in  acid  solution,  and  could  be  fixed  on  cotton  only 
when  it  was  previously  mordanted.  The  azo-colors  prepared 
from  tetrazodiphenyl  and  its  homologues  will  dye  cotton  without 
a  mordant.  The  first  of  these  series  of  colors  was  brought  into 
the  market  in  1884  by  the  Aniline  Manufacturing  Company 
of  Berlin  under  the  name  of  "Congo."  Since  that  time  the 
number  of  Congo  colors  has  increased  rapidly.  According  to 
Friedlander,  sixty  per  cent,  of  the  patents  for  color  prepara- 
tions taken  out  in  the  last  two  years — from  1886  to  1888 — relate 
to  the  preparations  of  these  colors.  The  manufacturing  of  azo- 
colors  has  slowly  reached  an  almost  incredible  extent.  The 
well-known  table  of  G.  Schultz  and  P.  Julius  shows  that  there 
are  120  different  azo-colors  in  the  market,  and  the  known  colors 
amount  to  ten  times  that  number. 

Chemical  Constitution. — The  azo-group  ( — N  =  N — ) 
is  found  in  two  classes  of  organic  bodies — the  azo-compounds 
and  the  diazo-compounds.  In  the  first,  it  is  joined  on  either 
side  by  a  benzene  residue  which  satisfies  the  valency.     In  the 


98 


THE    COAL-TAR    COLORS. 


second  series,  but  one  benzene  residue  is  present,  while  the 
other  valency  is  satisfied  by  a  radicle  of  another  type — hydroxyl, 
amidogen,  etc. 


Diazo  compounds. 

N  =  N  —  CI 


Azo- compounds. 

N     =^    N 


diazobenzene  chloride 
N  =  N  — NH 


azobenzene 

N     =     N 


diazoamidobenzene 


a-azonaphlhalene 


The  diazo-bodies  possess  no  coloring  power,  but  as  sources  of 
the  azo- colors  they  are  of  the  utmost  importance.  Fqt  the 
most  important  points  concerning  their  preparations  and  prop- 
erties, see  below.  The  azo-bodies,  on  the  other  hand,  are  col- 
oring substances,  but  not  dyes.*  Their  functions  as  dye-stuffs 
are  developed  only  by  the  introduction  of  an  acid  or  basic  group 
into  them.  Azobenzene,  for  instance,  is  a  yellow  body  that  has 
no  affinity  for  fibres.  The  azobenzenemonosulphonic  and  di- 
sulphonic  acids,  produced  by  the  introduction  of  the  sulphonic 
group  into  the  azobenzene,  are  bodies  of,  at  least,  weak  dyeing 
power.  More  powerful  influences  in  determining  the  coloring 
value  of  the  azo-bodies  belong  to  hydroxyl  or  amidogen.  Ami- 
doazobenzenedisulphonic  acid,  which  arises  from  the  simultan- 
eous introduction  of  amidogen  and  two  sulphonic  groups  into 
azobenzene,  is  a  useful  yellow  dye.  Its  sodium  salt  is  sold  under 
the  name  of  acid  yellow,  or  fast  yellow.  Hydroxyazobenzene- 
sulphonic  acid,  produced  by  the  simultaneous  introduction  of 


*  For  an  account  of  some  of  the  structural  conditions  on  which  the  forma, 
tion  of  dye-stuffs  depends,  see  Appendix. 


AZO-COLORS. 


99 


hydroxyl  and  a  sulphonic  group,  occurs  in  the  form  of  a  sodium 
salt  under  the  name  of  tropceolin  Y.* 

Production  of  the  Azo-colors. — Two  methods  only  need 
receive  notice.  First,  transformation  to  diazoamido-compounds, 
by  the  action  of  amines  on  amidoazo-compounds,  and  by  phenols 
to  hydroxyazo-bodies.  For  instance,  diazoamidobenzene,  by 
prolonged  heating  with  aniline  hydrochloride  at  30  to  40°  be- 
comes amidoazobenzene  hydrochloride.     (Kukele.) 

N  =  N—  NH 


NH2  HCl 


diazoamiflobenzene 


+ 


N 


N 


amidobenzene  hydrochloride. 

+ 

NH2  HCl 
/-amidoazobenzene  hydrochloride.  amidobenzene. 

In  the  same  manner  the  action  of  diazoamidophenol  pro- 
duces parahydroxyazobenzene  together  with  aniline.  (K.  Heu- 
man  and  Oeconomeides.) 

N  =  N  — NH  HO 

\ 


diazoamidobenzene. 

N       =       N 


+ 


HO 
/-hydroxyazobenzene. 


aniline. 


*  The  azarines  are  included  in  the  azo  colors,  although  they  more  probably 
contain  the  group — NH  —  N  r=:  rather  than  the  typical  azo-group  —  N  =^  N — . 


lOO  THE    COAL-TAR    COLORS. 

The  second  method  of  producing  azo  colors  is  by  the  action 
of  the  salts  of  the  diazo-compounds  upon  prinnary,  secondary, 
and  tertiary  amines.  These  produce  amidoazo-compounds. 
(See  Appendix.) 

N  =  N  —  CI  NH2  N  c::r  N 


diazobenzene  chloride.  aniline.  /-amidoazobenzene  hydrochloride. 


NH2  HCl 


This  method,  which  has  been  of  great  value  from  a  theoretical 
point  of  view,  is  almost  exclusively  followed  in  manufacturing 
operations.  Concerning  a  method  of  preparing  azo-colors  from 
quinone  and  hydrazines,  which  has  much  theoretical  interest,  see 
a  subsequent  paragraph.  Phenols  are  employed  in  alkaline  solu- 
tion. Amines  react  in  the  neutral  or  acid  solution.  The  color 
separates  either  immediately  or  after  long  standing.  \Wien  it 
does  not  precipitate,  sodium  chloride,  sodium  acetate,  and  oc- 
casionally acetic  acid,  or  hydrochloric  acid  are  added.  The  color 
is  purified  by  re-solution,  or  by  re-precipitation.  The  commer- 
cial azo-colors  are  almost  chemically  pure.  As  appears  from  the 
method  of  preparation,  they  cannot  contain  injurious  substances. 
Should  they  be  found  to  act  injuriously,  it  would  be  due  to  the 
color  itself,  and  not  to  any  foreign  substance.  In  additions  by 
way  of  dilution  or  reduction  (coupage)  it  must,  of  course,  be 
understood  no  injurious  substances  are  to  be  used.  This  is  almost 
always  the  case. 

Materials  Employed  for  the  Production  of  Azo- 
colors. — For  the  preparation  of  the  azo-colors,  inorganic  and 
organic  materials  are  employed.  Of  the  former,  potassium  and 
sodium  nitrites  are  especially  important,  since  these  are  em- 
ployed in  the  production  of  the  intermediate  diazo-compounds. 
Sodium  chloride,  sodium  hydroxide,  and  sodium  acetate  are 
also  employed  for  purposes  of  precipitation  and  for  forma- 
tion of  sodium  salts.     Sulphuric  acid  is  employed  for  sulphona- 


A20-C0L0RS.  lOI 

lion.  A  few  other  bodies  of  little  importance  are  also  used. 
Of  the  organic  bodies  two  classes  are  used  :  First,  the  sub- 
stances that  are  to  be  diazotized ;  secondly,  substances  which 
are  to  be  united  with  azotized  materials.  To  the  first  group 
belong  amines  and  their  sulphonic  acids.  To  the  second 
group,  primary,  secondary,  and  tertiary  amines,  phenols, 
hydroxy-acids,  and  the  sulphonic  acids  derived  from  these. 
It  is  not  my  purpose  to  enumerate  more  minutely  the  sub- 
stances employed  in  the  manufacture  of  these  bodies,  es- 
pecially as  in  view  of  the  constantly  increasing  list  the 
enumeration  would  be  incomplete.  I  will  mention  only  the 
following  :  — 

Group  I.  Aniline,  toluidine,  xylidine,  cumidine,  meta-  and 
paranitraniline,  and  meta-  and  paramidobenzenesulphonic 
acids,  a-  and  /J-amidonaphthalene  and  their  sulphonic  acids, 
metadiamidobenzene  and  benzidine,  tolidene,  dianisidene,  and 
diamidostilbenedisulphonic  acid.  Of  the  second  class  I  may 
mention  resorcinol,  salicylic  acid,  a-  and  /?  naphthol,  and  their 
sulphonic  acids,  and  diphenylamine.  It  will  be  necessary  to  dis- 
cuss briefly  the  important  naphtholsulphonic  acids,  and  amido- 
naphthalenesulphonic  acids,  since  a  knowledge  of  these  is  very 
important  in  comprehending  the  azo-colors. 

a-  and  ^-naphtholsulphonic  Acids. — By  the  action  of  concen- 
trated sulphuric  acid  on  /?-naphthol  there  are  formed  several 
isomeric  mono-  and  disulphonic  acids,  the  relative  proportion 
depending  upon  the  temperature  and  the  duration  of  the 
process.*  Four  isomeric  /S-naphtholmonosulphonic  acids  are 
known : — 


I.    Shaefl'er's  acid.  (     Y       1^0 

/5-naphthol-/?-monosulphonic  acid. 


•^According  to  Armstrong,  with  /?-naplithol  and  sulphuric  acid,  the  ether, 
/3-naphlhyl  acid  sulphate  is  first  formed  and  then  decomposed  into  the  two 
isomeric  acids. 


I02 


THE    COAL-TAR   COLORS. 


HSO 


II.   Bayer's  acid. 

/5-naphthol-«-monosulphoinc  acid. 


These  are  much  used  in  manufacturing  operations. 


III.  F-acid  (L.  Cassella  &  Co.).  HSO 
/J-naphthol-fJ-monosulphonic  acid. 

IV.  Dahl's  acid. 
/S-naphthol-;'-monosulphonic  acid. 


HO 


HO 


HSO, 


By  further  treatment  of  these  monosulphonic  acids  with  con- 
centrated sulphuric  acid,  naphtholdisulphonic  acids  are  ob- 
tained, of  the  /9-forms  of  which  three  isomers  are  known.  The 
exact  constitutional  formulae  are  not  perfectly  clear.  The  so- 
called  G-  acid  of  Meister,  Lucius  &  Briining  is  probably — 


HSO. 


HSO 


HO 


It  forms  a  sodium  salt  soluble  in  alcohol  (G-salt).    The  R-acid 
of  Meister,  Lucius  &  Briining,  the  sodium  salt   of  which    (R-- 
salt)  is  insoluble  in  alcohol,  is  probably — 


HSO, 


HSO.. 


HO 


It  furnishes  specially  useful  azo-colors.  A  third  disulphonic 
acid  (F-acid)  has  not  yet  been  closely  investigated.  The  three 
known  isomeric  «-naphtholmonosulphonic  acids  are  of  much  less 
importance  in  the  color-making  industry  than  the  corresponding 


AZO-COLORS. 


103 


/9-derivatives.  a-naphtholmonosulphonic  acid,  NW.  (Neville 
&  Winther)  is  prepared  from  «-amidonaphthalenesulpbonic 
acid  by  diazotizing  and  subsequently  decomposing  by  boiling. 
It  has  the  composition  : — 

HO 


The  second,  a-naphtholmonosulphonic  acid  C,  discovered  by 
Cleve,  has  probably  the  constitution  : — 


HO 


HSO, 


Two  a-naphtholdisulphonic  acids  are  also  known,  one  prepared 
by  Leo  Vignon,  known  as  LV. ,  and  another  by  Sch511kopf  & 
Co.,  known  as  Sch. 

Of  the  a-amidonaphthalenesulphonic  acids,  practically  only 
one  is  used  in  manufacturing  operations.  This  is  Piria's,  com- 
monly known  as  naphthionic  acid.     Its  constitution  is  probably 

NHo 


HSO, 


/5-amidonaphthalenesulphonic  acids  are  largely  employed  in 
the  preparation  of  the  Congo  group.  Three  isomeric  acids  of 
this  constitution  are  better  known.  First,  the  a-acid  corresponds 
to  the  Bayer's  acid  : — 

HSO, 


NH, 


I04  THE    COAL-TAR   COLORS. 

The  /?-acid  corresponds  to  Schaeffer's  acid. 


HSO 
The  /'-acid  is  probably 


NH, 


HSO 


NH. 


The  <?-acid  is  doubtless  a  mixture  of  the  /?-acid  with  a  new 
(F-)acid.    . 

A  /?-amidonaphthalenedisulphonic  acid  prepared  from  /5-nitro- 
naphthalenedisulphonic  acid  by  reduction  has  been  used  in  the 
arts. 

It  is  established  that  many  of  the  materials  enumerated  above 
as  employed  in  the  manufacture  of  azo  colors  are  poisonous,  or 
at  least,  injurious.  It  would  be  unsafe,  however,  to  infer  a  priori 
from  the  poisonous  nature  of  the  materials  employed,  a  poisonous 
character  in  the  colors,  since  any  excess  of  these  bodies  is  en- 
tirely removed  during  the  process  of  manufacturing  and  purifica- 
tion, as  has  been  noted  above. 

Decompositions  and  Transformations.  —  Reducing 
agents,  for  instance,  zinc  dust  mixed  with  water,  ammonium  hy- 
droxide, sodium  hydroxide  or  dilute  acids ;  stannous  chloride  or 
ammonium  sulphide,  decompose  the  azo-colors  by  separating 
the  two  nitrogen  atoms  in  the  azo-group  and  forming  two  ami- 
dogen  groups, 

R  _  N  ^  N  —  R^  4-  H4  -^  R  —  NH2  -f  R^NHg. 


N        :.=        N 


NH, 


NH. 


\   H. 


Azobenzene. 


Aniline. 


AZO-COLORS 

• 

I 

—     N 

NH, 

mi. 

+  II4          = 

\y 

zobenzene 

Aniline. 

p- 

diamidobenzene 

105 


This  reaction  is  especially  important,  because  it  has  in  many 
cases  enabled  us  to  determine  the  constitution  of  the  azo-colors. 
When,  for  instance,  hydroxyazobenzene  is  converted  by  reduc- 
tion into  paramidohydroxybenzene  and  aniline,  the  nitrogen  and 
hydroxyl  groups  will  assume  the  para-position. 


N 


N 


NH. 


NFL 


gives 


HO 


HO 


Amidoazobenzene  gives  by  reduction  paradiamidobenzene  \ 
therefore,  the  nitrogen  and  amidogen  groups  must  have  occupied 
in  this  color  the  para-position,  thus :  — 


N     =     N 


NH. 


NH, 


produces 


/\  /\ 


+ 


NH, 


NH, 


Azo-colors  with  free  hydroxyl  groups  dissolve  generally  in 
sodium  hydroxide,  and  give  characteristic  reactions.  (For  ex- 
ceptions see  below.)  Concentrated  sulphuric  acid  gives  with 
most  azo-colors  very  distinct  color  reactions,  which  are  advan- 
tageously used  for  distinguishing  various  dyes.  Spectroscopic 
examinations  of  these  solutions  may  be  employed  in  the  practi- 
cal recognition  of  these  substances. 

Constitution. — In  the  junction  of  a  diazo-compound  with 
a  phenol  or  amine  the  position  of  the  azo-group  ( —  N  =  N — ) 
in  reference  to  the  hydroxyl  or  amine  is  dependent  upon  the 
following  conditions  :  When   the  carbon   atom  which  is  joined 

9 


io6 


THE    COAL-TAR    COLORS. 


to  the  azo-group  has,  in  the  para-position,  another  carbon  atom 
joined  to  hydrogen  alone,  the  amidogen  or  hydroxyl  group  will 
take  a  para-position  to  the  azo-group. 


N  =  N  —  CI 


+ 


NH, 


N 


N 


diazobenzene  chloride.         aniline. 


NH2HCI 


/-amidazobenzene  hydrochloride. 

This  is  the  most  frequent  and  most  important  class. 
If  the  para-position,  i.e.,  the  hydrogen   at  that  point,  is  re- 
placed by  a  radicle,  the  azo-group  takes  the  ortho-position. 
N  =  N  —  CI        HO  HO 


+ 


N=:N 


+  NaCl 


NaSO, 


\/    \y 


sodium  phenolsulphonate. 


HSO3 

(7-hydroxy-/-azobenzftne 
sul  phonic  acid. 


The  attaching  of  the  azo-group  to  the  meta-position  when 
other  radicles  are  present  in  the  ortho-  or  para-position  has  not 
yet  been  observed. 

With  a-naphthol  and  a-amidonaphthalene  the  azo-group 
takes  the  para-position  to  the  hydroxyl  as  long  as  this  is  unsub- 
stituted.  If  the  hydrogen  atom  of  the  para-position  is  substituted, 
the  azo-group  takes  the  ortho-position.* 

N  =  N  HO  N    =    N 

+ 


SO3 

/-diazobenzene  sul- 
phonic  anhydride. 


a-naphthol. 


HSO3       HO 
a-  naphthol-/-azobenzene 
sulphonic  acid. 


/?-naphthol  and  /?-amidonaphthalene  have  no  hydrogen  atom 
standing  in   the   para-position    to   the  hydroxyl  group.     When 

*  According  to  Friedlander,  ortho-  as   well  as  para-compounds  are  formed 
when  the  para-position  is  unsubstituted. 


AZO-COLORS. 


107 


/?-naphtliol  is  joined,  the  azo-groiip  takes  the  adjoining  /^-position 
(ortho-position)  to  the  hydroxyl. 

N    =    N  N        =       N 


+ 


SO, 


HO 


HO 


HSO3 

/3-naphthol-/-azobenzene- 
sulphonic  acid. 


The  correctness  of  the  constitutional  formulae  assumed  in  the 
above  reactions  is  inferred  from  the  reduction  products  of  the 
resulting  azo-colors,  instances  of  which  have  already  been  pre- 
sented. However,  the  close  study  of  these  reduction  products, 
as  far  as  the  more  complex  forms  are  concerned,  has  just  begun. 

Those  azo-bodies  which  result  from  a  conjugation  of  diazo- 
salts  with  ,5-naphthol  and  ^5-amidonaphthalene  must  have  a  dif- 
ferent constitution  from  the  colors  heretofore  indicated.  If  the 
azo-colors  prepared  from  j5-naphthol  were  true  hydroxyazo- 
compounds  they  should  be  by  reason  of  the  free  hydroxyl  group 
soluble  in  alkali,  as  are  the  derivatives  of  /S'-naphthol,  but  they 
are  insoluble.  For  this  reason  C.  Liebermann  has  formulated 
anilineazo-/5-naphthol,  not — 


but  as 


CeH^  _  N  =  N  -  q^Hg  HO  (/3) 


Q"5  -  N   -  NH  -    C,,U, 


L 


o 


Zincke   formulated    the   corresponding    product    from   diazo- 
benzene  chloride  and  ^J-amidonapbthalene,  not 


but 


or  as 


C6H5  -  N  =  N  -  C^oHg  NH,  (/3) 


CeH-  _  NH  -  N 


HN- 


^10"6 


J 


QH,      -      N    -    NH 

N  H 


CioHs 


io8 


THE   COAL-TAR   COLORS. 


A  different  formula  is  also  supposable  for  the  a-naphthol  azo- 
colors,  when  we  consider  their  origin  from  quinone  and  phenyl 
hydrazine :  — 


NH., 


+  H,0 


CO  HO 

a-naphthoquinone.  Phenylhydrazine.      a-naphthoquinonephenylhydrazine 

=  benzene-/-azo-a-naphthol. 

The  a-naphthoquinonephenylhydrazine  obtained  in  this  reac- 
tion is  wholly  identical  with  the  benzeneazo-a-naphthol  obtained 
from  diazobenzene  chloride  and  a-naphthol,  while  the  products 
of  the  action  of  diazobenzene  chloride  and  /5-naphthol,  and 
phenylhydrazine  and  /3-naphthoquinone,  although  isomeric  are 
different  in  properties. 

Solubility,  Color,  Deportment  with  Fibres. — The  azo- 
colors  employed  in  the  industries  are  mostly  soluble  in«water. 
They  owe  this  solubility  to  the  presence  of  one  or  more 
sulphonic  groups.  For  instance,  dimethylazobenzene  (butter- 
yellow)  is  soluble  only  in  alcohol,  ''spirit  soluble,"  while  the 
sulphonic  acid  derived  from  it  (helianthin,  methyl  orange)  is 
easily  soluble  in  water.  To  introduce  sulphonic  groups  into  azo- 
colors,  three  methods  are  available  : — 

(/2)  The  prepared  but  insoluble  color  is  treated  directly  with 
strong  sulphuric  acid  (sulphonation). 

{b)  The  sulphonic  group  is  first  introduced  into  the  diazotized 
body,  or  into  the  phenol  or  amine  which  is  to  unite  with  the 
diazo-salt.  Thus,  by  diazotizing  pure  amidobenzene-sulphonic 
acid,  and  joining  it  with  dimethyl  aniline,  we  obtain  a  soluble 
methyl  orange. 


NH, 


N  =  N 


-f  HNO. 


HSO, 


-f  2H2O 


SO. 


/-amidobenzene  sulphonic  acid.        /-diazobenzene  sulphonic  anhydride. 


N^N 


AZO-COLORS. 

N(CH3), 


SO. 


■+ 


Dimethylaniline. 


109 


N     ==     N 


HSO 


N(CH3), 


Methyl  orange. 
Helianthin. 


Recently  a  third  method  was  discovered  for  producing  soluble 
azo-colors.  E.  Spiegel  showed  that  insoluble  azo-colors  could  be 
converted  into  soluble  forms  by  the  addition  of  ammonium  acid 
sulphite,  or  sodium  acid  sulphite,  which  combinations  are  called 
azarines. 


C6H2HOC12  —  N 


N- 


^10^6^0 


+ 


Dichlorphenol-azo-/3-naphthol. 


NH^HSOg     = 


Acid  ammonium  sulphite. 


C6H2HOC]2 


NH  —  N  —  CioHgHO 


NH^SOs 


Azarine  S. 


The  azarines  decompose  by  the  influence  of  heat  or  alkali 
readily  into  the  original  color  and  neutral  sulphite.  This  prop- 
erty is  utilized  in  dyeing  and  printing.  The  azarine  is  dyed  or 
printed  on  the  fibre  and  the  compound  is  then  split  by  heat  or 
an  alkaline  bath.  The  color  is  fixed  in  the  insoluble  form  and 
the  soluble  sulphite  is  washed  out. 

Yellow,  red,  brown,  blue,  violet,  indeed,  almost  black,  azo- 
colors  have  been  obtained,  but  the  production  of  a  green  azo- 
color  seems  to  be  as  yet  unaccomplished.  Most  of  the  azo- 
colors  are  acid,  the  basic  members  being  quite  limited  in  number. 
Among  these  latter  are  included  chrysoidin,  metadiamidoazo- 
benzene  hydrochloride. 


NHjHCl 

NHoHCl 


\y     \y 


no  THE    COAL-TAR    COLORS. 

and    Bismarck    brown,    probably    triamidoazobenzene    hydro- 
chloride, 

N  =  N 


NH^ 


NHjHCl 


\y  \y 


NHjHCl 


The  soluble  azo-colors  which  contain  sulphonic  groups  find 
widest  application  in  wool  dyeing.  The  color  vat  is  charged  with 
sulphuric  acid  and  sodium  sulphate,  practically  sodium  acid 
sulphate,  technically  known  as  cream  of  tartar  preparation. 
By  this,  the  color  becomes  less  soluble  and  deposits  more  slowly 
upon  the  fibre.  Silk  is  but  rarely  dyed  with  azo-colors.  Up 
to  a  recent  period,  cotton  could  not  be  dyed  with  them  except 
with  the  employment  of  a  mordant,  but  lately  a  class  of  azo- 
colors  known  as  Congo  dyes  have  been  obtained,  which  dye 
cotton  in  the  ordinary  soap  bath.  Metallic  compounds  of  the 
azo-colors  (lakes)  serve  for  the  coloring  of  paper.  The  colors 
insoluble  in  water  but  soluble  in  alcohol  are  used  for  the 
painting  of  wood,  leather,  and  metals,  being  dissolved  in  lacquer 
or  varnish.  Azo-colors,  both  water  and  spirit  soluble,  are  used  in 
considerable  amount  for  the  coloring  of  food  and  drink.  The 
spirit  soluble  are  used,  for  instance,  for  the  coloring  of  alcoholic 
beverages  and  liqueurs.  Of  the  water  soluble  forms,  aniline  yel- 
low (spirit  yellow)  is  employed  for  coloring  noodles. 

Cazeneuve  indicates  the  following  colors  as  being  used  for  the 
coloring  of  wines :  Bismarck  brown  (phenylene  brown),  chry- 
soidin,  aniline  yellow,  acid  yellow,  (solid  yellow),  various 
ponceaux,  fast  red,  (roccellin),  rouge  purple,  tropaeolin,  metanil 
yellow,  azoflavin. 

Typical  Reactions  of  the  Group — A  characteristic  reaction 
common  to  all  azo-colors  and  easily  performed  is  as  yet  unknown. 
By  reducing,  they  are,  as  is  the  case  with  many  other  colors,  de- 
colorized. The  products  of  reduction  are  generally  only  to  be 
recognized  by  an  intricate  chemical  analysis  and  with  the  employ- 
ment of,  at  least,  a  gram  of  pure  substance.     In  most  cases  the 


AZO-COLORS.  1 1 1 

reduction  products  do  not  yield  by  oxidation  the  original  material 
but  indigo  and  azines  (<?.  g.,  safranine)  yield  by  reduction  color- 
less bodies,  and  by  oxidation,  even  when  standing  in  contact 
with  the  air,  the  original  color  is  reproduced.  The  colorless  re- 
duction products  of  the  rosolic  acid  series  are  not  reconverted  to 
rosolic  acid,  etc.,  by  oxidation,  but  these  bodies  are  free  from 
nitrogen,  and,  therefore,  easily  distinguished  from  the  azo-colors. 
The  alkalies  change  the  tint  of  azo-colors  in  a  variety  of  ways, 
but  decoloration  never  takes  place,  as  in  the  case  of  fuchsin. 

From  these  considerations  it  will  appear  that  the  recognition 
of  any  body  as  an  azo-color  is,  even  for  the  expert,  no  easy  task, 
especially  when  little  material  is  at  hand,  or  when  the  determi- 
nation is  to  be  made  upon  the  fibre.  The  artificial  coloring 
of  food  can  be  detected,  therefore,  only  under  specially  favor- 
able conditions.  The  first  practicable  method  for  determining 
these  colors  was  that  given  by  Witt.  Weingartner,  Lepetit,  and 
Martinon  worked  in  the  same  direction.  Further  assistance  in 
these,  to  say  the  least,  not  very  satisfactory  investigations, 
has  been  furnished  by  Kertesz,  G.  Schultz,  and  P.  Julius. 
When  we  are  examining  the  secretions  and  excretions  of 
animals  for  a  color  that  has  been  exhibited  with  the  food, 
a  task  with  which  the  author  of  this  book  has  been  much 
concerned,  the  practical  methods,  outside  of  chemical  and 
spectroscopical  tests  are  the  dyeing  of  wool,  silk,  or  cotton  by 
the  color.  Of  course,  for  such  a  test  the  liquid  examined, 
generally  urine,  must  be  prepared  in  the  same  manner  as  the 
dyer  prepares  the  bath.  Occasionally,  mordanting  the  fibre 
will  be  advisable.  I  need  not  recall  the  fact  that  this  method 
has  been  used  by  other  investigators  for  the  detection  of  small 
quantities  of  colors,  being  often  used  for  the  detection  of  fuchsin 
in  wine,  or  of  picric  acid  in  beer.  The  color  precipitated  upon 
the  fabric  may  then  be  recognized  and  identified  by  chemical 
reaction.  On  the  detection  of  azo-colors  in  wine,  we  have 
a  considerable  number  of  investigations  mostly  of  French  origin. 
Caution  against  too  great  confidence  in  the  spectroscope  for  these 
observations  must  be  expressed,  for  it  is  known  that  constant 


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112 


AZO-COLORS.  113 

conditions  of  solvent,  concentration  and  illumination  must  be 
observed.  I  wholly  agree  with  Cazeneuve's  statement :  **  We 
may  observe,  that  although  the  spectra  of  the  azo-colors  differ 
but  little  among  themselves,  they  are  distinguished  sharply 
from  those  of  fuchsin,  cochineal,  and  archil." 

Commercial  and  Scientific  Designations. — As  set  forth 
above,  the  artificial  colors  bear  in  commerce  mostly  arbitrary 
names,  and  justly,  for  scientific  names,  while  they  express 
the  molecular  structure,  are  so  long,  intricate  and  unpleasant 
that  their  use  is  prevented.  Examples  are  given  above.  Pro- 
posals for  simplying  the  nomenclature  have  not  been  lacking, 
and  none  of  these  accomplish  the  purpose  better  than  the 
one  proposed  by  G.  Schultz. 

As  has  been  set  forth,  each  azo-color  consists  of  two  parts,  a 
diazotized  base  and  a  phenol  or  amine,  which  is  joined  to  it. 
In  Schultz's  method  for  naming  the  azo-colors  the  body  from 
which  the  diazo-compound  has  been  prepared  is  first  named, 
then  follow  the  syllable  "  azo,"  then  the  name  of  the  phenol  or 
amine  to  which  the  diazo-compound  is  joined.  In  the  diazo- 
colors  containing  the  azo-group  ( —  N  =  N  — )  twice,  the  diazo- 
tized base  is  separated  from  both  the  components  by  the  word 
disazo.  I  have  adopted  this  proposal  since  it  has  shown  itself  to 
be  practical.  A  few  samples  are  given  in  the  annexed  table. 
From  the  instances  there  given  it  will  appear  that  even  so  com- 
plicated a  compound  as  Congo-red  receives  a  name  relatively 
simple  and  intelligible  to  the  chemist. 

Classification  of  the  Azo-colors.* — As  a  basis  for  classi- 
fying the  azo-colors  we  can  take  the  number  of  the  azo-groups 
contained  in  a  molecule,  distinguishing  two  classes,  inonazo-  and 
disazo-,  accordingly  as  they  contain  one  or  two  such  groups. 
The  former  class  can  be  subdivided  into  hydroxazo-cojupounds 
and  amidoazo-comJ)oii?ids,  according  to  whether  they  arise  from 
the  junction  of  a  diazo-salt  with  a  hydroxy-  or  an   amido-com- 


*  For  illustrative  formuliTe  and  reactions  of  the  main   groups  of  azo-colors, 
see  Appendix. 
10 


114  THE    COAL-TAR    COLORS. 

pound.  Both  these  classes  of  bodies  may  be  either  sulphonated 
or  not.  This  group  includes  a  large  number  of  azo-colors,  and, 
in  fact,  those  first  discovered.  It  includes  the  azarins,  which 
were  sufficiently  described  previously. 

In  agreement  with  Schultz,  we  may  divide  the  disazo-colors 
into  three  groups  : — 

(a)  Prwiary  Disazo-colors. — These  originate  from  the  action 
of  two  similar  or  dissimilar  diazo-salts  upon  a  single  amine  or 
phenol.  Fast  brown  belongs  here.  It  is  produced  by  the 
action  of  two  molecules  of  diazonaphthalenesulphonic  acid 
upon  one  molecule  of  resorcinol. 

(^)  Seconda?y  Disazo-colors, — These  arise  by  the  diazotizing 
of  a  diazo-compound  containing  a  free  amidogen  group,  and  a 
junction  of  the  compound  so  obtained  with  amines  or  phenols. 
Some  very  valuble  dyes  are  included  in  this  group.  Biebrich  scar- 
let, for  instance,  is  produced  by  the  diazotizing  of  amidoazoben- 
zenesulphonic  acid,  and  the  junction  of  the  diazo-compound  so 
obtained  with  /?-naphthol. 

{c)  Azo-colors  of  the  Congo  Group. — These  are  so  called  from 
the  principal  member  of  the  group,  Congo  red.  They  are 
derived  from  benzidine,  and  its  homologues  by  diazotizing  and 
joining  to  similar  and  dissimilar  molecules  of  a  phenol  or  amine. 
By  diazotizing  benzidine,  the  so-called  letrazo-compoimds  arise, 
which  name  is  derived  from  the  four  nitrogen  atoms  the  molecule 
contains.  Bodies  of  the  Congo  group  are,  therefore,  also  called 
tetrazo-dyes.  They  dye  cotton  fast  to  washing,  without  a  mor- 
dant, which  property  distinguishes  them  from  all  other  known 
azo-colors. 

OBSERVATIONS  ON  ANIMALS. 
Records  from  Other  Experimenters. — We  are  indebted  to 
Cazeneuve  and  Lepine  for  able  researches  as  to  the  effect  of  azo- 
colors  upon  human  beings  and  the  lower  animals,  the  results  of 
which  are  exhibited  in  the  following  list  *  : — 

*  The  name  in  quotation  marks  is  the  title  given  in  the  original  French 
work.     The  titles  in  parentheses  are  the  synonyms. 


OBSERVATIONS    ON   ANIMALS.  II5 

'*  Rouge  soluble  "  (azorubin  S,  fast  red  C,  carmoisin)  is  not 
poisonous  to  human  beings. 

"Rouge  poupre  "  (new  coccin,  brilliant  ponceau,  cochineal 
red,  or  fast  red  D,  Bordeaux  S,  amaranth,  acid  azorubin  2B), 
not  poisonous  to  human  beings. 

''  Bordeaux  B  "  (fast  red  B),  not  poisonous  to  human  beings. 

**  Ponceau  R"  (ponceau  2R,  xylidin  red,  xylidin  ponceau), 
not  poisonous  to  dogs,  either  by  administration  by  stomach  nor 
injection  into  blood. 

''Orange  I"  (a-naphthol  orange,  tropseolin  000),  same  as 
ponceau  R. 

"Solid  yellow"  (fast  yellow  R,  acid  yellow  R,  yellow  W), 
not  poisonous  to  dogs,  either  when  administered  by  the  stomach 
or  injected  into  blood.     Poisonous  to  human  beings  (?). 

The  azo-colors  included  in  the  above  investigations  belong  to 
the  monazo-group  and  are  all  harmless. 

Weyl's  Researches. — My  own  investigations  on  monazo- 
colors  are  set  forth  in  the  following  list : — 

Non-poisonous:  Bismarck  brown,  Soudan  I,  ponceau  4GB, 
archil-substitute,  chrysoidin,  diphenylamine  orange,  azarin  S, 
;;/-nitrazotin,  /-nitrazotin. 

Poisonous  :   Orange  II,  metanil  yellow. 

To  this  I  make  the  following  comment  concerning  the  selec- 
tions of  the  colors.  R  —  N  =  N  —  R  —  Gr.  denotes  an  azo- 
color.  R  stands  for  CgHg,  R^  for  CioHg,  Gr.  for  a  salt-forming 
group.  I  desired  to  learn  if  the  entrance  of  certain  groups  (Gr.) 
into  the  azo-color  exercise  an  influence  upon  its  toxic  action.  To 
this  end,  I  started  with  the  color  which  had  been  produced  by  the 
combination  of  diazobenzene  chloride  with  /3-naphthol  (Soudan 
I).  I  introduced  into  this  color,  a  nitro-group  which  stood  in 
the  benzene  nucleus  in  the  meta-position  to  the  azo-group.  The 
azo-color  (/>»2-nitrazotin)  was  thus  produced.  The  influence  of 
the  sulphonic  group  could  be  thus  indicated.  This  may  be 
attached  either  to  the  benzene  or  to  the  naphthalene  nucleus, 
/-nitrazotin  contains  at  the  same  time  a  nitro-  and  a  sulphonic 
group,  while  archil-substitute,  which  is  derived  from  the  a-amido- 


Il6  THE    COAL-TAR    COLORS. 

naphthalene,  also  contains  nitro-  and  sulphonic  groups.  Un- 
fortunately, further  investigations  directed  to  the  introducing 
of  other  groups  into  the  color  molecule,  in  order  to  obtain 
information  as  to  their  influence  upon  the  toxic  action  of  the 
body  so  produced,  were  frustrated,  because  other  intermediate 
products  were  not  obtainable  by  me.  Bismarck  brown  and 
chrysoidin  are  much  used.  Azarin  S  has  not  been  examined. 
Diphenylamine  orange  and  metanil  yellow  are  isomeric. 

Bismarck  Brown. 

This  color,  also  known  as  Manchester  brown,  phenylene 
brown,  Vesuvin,  aniline  brown,  leather  brown,  cinnamon  brown, 
canelle,  English  brown,  and  golden  brown,  is  produced  by  the 
action  of  two  molecules  of  sodium  nitrite  on  three  molecules 
of  ;;/-diamidobenzene  hydrochloride  in  watery  solution.  It  is 
not  positively  established  whether  it  is  triamidoazobenzene 
hydrochloride,  as  usually  assumed,  ^ 


N     =     N 


NH. 


NH^HCl 


NH„HC1. 


or,  more  probably,  a  compound  of  w-diamidobenzenedisazo-;;^- 
diamidobenzene.  The  latter  form  is  the  more  probable  from  the 
mode  of  formation,  and  in  this  case  Bismarck  brown  would  belong 
to  the  disazo-colors. 

Typical  Reactions. — Dark-brown  powder,  producing  a  brown 
solution  in  water,  which  gives  with  hydrochloric  acid  a  brown 
precipitate  easily  soluble,  and  with  acetic  acid  a  brown  solution, 
but  no  precipitate ;  with  sodium  hydroxide,  a  brown  precipitate 
difficultly  soluble  ;  with  ammonium  hydroxide,  a  brown  precipi- 
tate soluble  in  excess,  and  with  ammoniacal  copper  solution,  a 
brown  precipitate  difficultly  soluble  in  hot  water,  reappearing  on 
cooling.  The  powder  dissolves  in  concentrated  sulphuric  acid 
to  a  brown  solution  which  becomes  reddish  on  dilution.  Bismarck 


OBSERVATIONS    ON    ANIMALS.  II  7 

brown  is  one  of  the  earliest-discovered  azo-colors,  but  is  still 
used  to  a  large  extent  for  the  coloring  of  wool,  leather,  and  jute. 
Cotton  is  dyed  only  after  previous  mordanting  with  tannin  and 
tartar  emetic.  The  specimens  used  in  the  experiment  were  from 
the  Aniline  Manufacturing  Company  of  Berlin.* 

Exp.  T. — Dog  weighing  5690  grams,  selected  June  nth,  and  on 
that  and  the  following  day  showing  no  albumin  in  the  urine.  On 
June  13th,  at  10.30  A.  M.,  2  grams  were  administered  by  the  oesopha- 
geal tube.  At  12  vomiting  occurred.  June  14th,  10  o'clock,  2  grams  : 
vomiting  at  12,  no  food  taken.  June  15th,  no  food  taken,  animal 
moved  about  a  little.  June  i6th,  2  grams,  two  hours  after  which 
marked  vomiting  occurred.  June  17th  to  20th,  no  nourishment  taken 
except  water.  June  21st,  food  taken,  animal  more  lively,  albumin  in 
urine.  June  22d,  5  grams,  animal  vomiting  for  one-half  hour  after 
administration.  June  23d  to  27th,  almost  no  food  taken,  albumin  in 
urine.  June  28th,  improving.  June  30th,  food  taken,  albumin  in 
urine.  Animal  was  under  observation  until  July  15th.  Finally  only 
slight  traces  of  albumin  were  detected  in  the  urine  and  the  appetite 
was  restored. 

Exp.  2. — Dog  weighing  29500  grams,  selected  April  29th,  was 
found  to  have  no  albuminuria.  On  April  30th,  received  5  grams  by 
the  oesophageal  tube.  May  ist,  urine  brown,  animal  lively,  appetite 
normal.  May  2d,  5  grams  by  the  tube.  Bismarck  brown  was  recog- 
nized in  the  urine  by  dyeing  wool  and  chemical  tests.  May  4th,  5 
grams  administered.  Urine  brownish,  no  albumin.  May  5th,  urine 
normal,  no  color,  no  albumin.  May  8th,  15  grams  administered. 
Animal  vomited  once  after  the  administration.  May  12th,  ate  little, 
seemed  sick.  May  14th,  seemed  lively.  May  15th,  15  grams  given  ; 
vomited  after  the  administration.  May  i6th,  no  food  taken,  no 
albuminuria.  May  i8th,  animal  normal.  May  22d,  normal.  Weight 
28900  grams. 

Exp.  J. — Dog  weighing  5500  grams,  received  during  an  entire 
month,  daily,  .25  gram  of  Bismarck  brown  with  its  food.  The  animal 
continued  in  good  health  during  the  entire  time,  did  not  vomit  and 
ate  as  usual.     It  gained  during  the  experiment  about  350  grams. 

Exp.  4. — Dog  weig^hing  63CO  grams,  received  in  the  course  of  20 

[*  I  have  found  traces  of  copper  in  all  the  commercial  samples  of  Bismarck 
brown  I  have  tested. — Trans.] 


Il8  THE   COAL-TAR   COLORS. 

days,  9  injections,  each  .i  gram,  of  Bismarck  brown  in  8-10  c.  c.  of 
sterilized  water  inserted  below  the  skin  of  the  back.  The  animal  re- 
mained entirely  normal.  Urine  was  normal  color  and  contained  no 
albumin. 

Exp.  J. — Same  animal  received  three  injections  of  .1  gram  each 
of  Bismarck  brown  in  8-10  c.  c.  of  sterihzed  water  introduced  into  the 
abdominal  cavity.  Animal  showed  slight  elevation  of  temperature 
and  refused  food.  Urine  remained  uncolored,  and  in  a  week  the 
animal  had  completely  recovered. 

Bismarck  brown  produces,  when  administered  to  dogs  by  the 
stomach,  even  in  doses  of  .35  gram  per  kilo  of  body-weight, 
vomiting  and  albuminuria.  Further  disturbance  is  not  noted, 
even  with  large  doses.  Small  doses,  .045  gram  per  kilo  of  body- 
weight,  even  when  frequently  administered,  seem  to  be  entirely 
harmless.  Doses  of  .016  gram  are  harmless,  even  when  intro- 
duced into  the  subcutaneous  cellular  tissue.  The  same  dose  in- 
troduced into  the  abdominal  cavity  induces  slight  disturbances. 
With  small  doses  the  urine  remains  uncolored.  Only  when  con- 
siderable quantities  are  administered  does  the  unaltered  'color 
appear  in  the  urine. 

Soudan  I. 

This  was  first  prepared  by  C.  Liebermann  from  diazobenzene 
chloride  and  /5-naphthol.  The  material  used  in  my  investigations 
was  prepared  by  myself  in  this  manner.  I  obtained  the  color 
by  recrystallization  from  90  per  cent,  alcohol  in  beautiful  red 
crystals.  It  is  employed  in  coloring  lacquers,  oils,  and  liqueurs. 
It  is  aniline-azo-/?-naphthol :  — 

N     =     N 

HO. 


Typical  Reactions. — In  the  pure  form  it  is  in  red  crystals,  in- 
soluble in  water,  soluble  in  alcohol,  to  an  orange-red  solution.  The 
alcoholic  solution  produces,  with  aqueous  sodium  hydroxide  or 
ammonium  hydroxide,  a  red-brown  solution.  With  ammoniacal 
copper  solution,  a  brown  precipitate.     The  powder  dissolves  in 


OBSERVATIONS    ON    ANIMALS.  II9 

concentrated  sulphuric  acid   to  a  fuchsin-red  liquid,  which  on 
dihition  with  water  yields  an  orange-yellow  precipitate. 


Exp.  I. — Dog  weighing  11900  grams,  selected  June  7th,  il 
Urine  alkaline,  no  albumin.  June  8th,  2  grams  administered  by  the 
tube.  June  9th,  no  administration.  Urine  normal  color,  alkaline,  no 
albumin,  sulphates  abundant.  The  distillate  obtained  from  the  urine, 
strongly  acidulated  with  hydrochloric  acid,  gave  a  distinct  precipitate 
with  bromine  water.  June  loth,  no  administration.  June  nth,  2 
grams  by  the  tube.  Animal  lively,  normal  fasces.  June  12th,  vomit- 
ing, but  otherwise  lively.  Urine  almost  free  from  phenol.  Two 
grams  by  the  tube  same  date.  June  13th,  2  grams  administered. 
Urine  now  dark  brown,  alkaline,  albumin  distinctly  present,  also  sul- 
phates. June  15th,  2  grams.  June  i6th,  animal  lively,  took  food. 
Weight  II 550 grams,  therefore  lost  350  grams  in  ten  days.  June  22d, 
animal  lively.  Urine  normal  in  color,  no  albumin.  June  23d,  5 
grams  administered.  Urine  rather  darker  than  normal.  June  24th, 
took  little  food.  June  25th,  5  grams  administered,  but  little  food  taken, 
June  26th,  faeces  yield  to  hot  alcohol  much  of  the  unchanged  dye 
stuff,  which  by  cooling  with  the  solvent  is  deposited  in  red  crystals 
and  gives  the  above  reaction.  Very  little  albumin  in  the  urine.  June 
27th,  animal  lively,  but  little  appetite.  June  29th,  food  taken,  urine 
uncolored.     June  30th,  animal  lively,  very  little  albumin  in  the  urine. 

The  color,  in  the  doses  administered,  is  not  entirely  harmless, 
since  a  limited  albuminuria  seems  to  be  brought  about.  From 
want  of  a  suitable  solvent,  subcutaneous  injections  could  not  be 
made. 

Metanitrazotin. 

This  an  azo-color,  which  seems  not  to  have  been  described.  I 
obtained  it  by  the  conjugation  of  diazotized  ;//-nitraniline  with 
^-naphthol.  Its  mode  of  formation  suggests  the  following  form- 
ula : — 

■    ■  N     =     N 

^    .HO. 
NO., 


It  may  be  called  ;;z-nitranilineazo-/?-naphthol. 

It  is  scarcely  soluble  in  90  per  cent,  alcohol,  difficultly  soluble 


I20  THE    COAL-TAR    COLORS. 

in  benzene  and  glacial  acetic  acid.  It  is  dissolved  in  warm  alco- 
holic solution  of  sodium  hydroxide,  filtered,  and  precipitated 
with  hydrochloric  acid.  The  precipitate  is  freed  from  the  ad- 
hering liquid  by  the  aspirator  and  washed  with  hot  water.  It 
presents  the  form  of  a  red  powder.  The  alcoholic  solution  pro- 
duces, with  sodium  hydroxide  and  ammonium  hydroxide,  a 
Burgundy-red  solution  which  is  changed  to  yellow  by  acids.  The 
powder  dissolves  in  concentrated  sulphuric  acid  to  a  fuchsin-red 
liquid  which  changes  to  orange-yellow  by  dilution  with  water, 
and  gives  a  greenish-yellow  fluorescence,  possibly  by  reason  of  a 
very  finely  divided  precipitate. 

Exp.  /. — Dog  weighing  12600  grams,  selected  July  nth,  showed 
traces  of  albumin  in  the  urine.  July  12th,  same  condition.  One  gram 
by  the  oesophageal  tube.  Urine  pale,  alkaline,  traces  of  albumin,  but 
phenol  hardly  recognizable.  July  13th,  2  grams  administered.  Urine 
abundant,  pale  yellow,  turbid,  strongly  alkaline;  addition  of  acid 
causes  strong  effervescence ;  no  sugar,  traces  of  albumin,  no  phenol. 
July  14th,  2  grams  by  the  tube.  Urine  strongly  alkaline.  July  15th, 
2  grams  by  the  tube.  Urine  abundant.  July  i6th,  animal  tively  ; 
weight,  12,450  grams,  consequently  a  loss  of  150  grams  in  five  days. 

A  second  dog,  weighing  5600  grams,  received  ten  doses  of  i  gram 
each  during  twenty  days.  Animal  remained  lively,  urine  free  from 
albumin  and  not  abnormally  colored.  It  was  under  observation  for 
five  weeks. 

I  supposed,  in  view  of  the  observations  made  on  nitro-colors, 
that  metanitrazotin  would  be  poisonous,  but,  in  spite  of  the 
nitro-group  that  is  present,  it  is  shown  to  be  harmless. 

Paranitrazotin. 

I  prepared  this  color  from  diazotized  /-nitraniline  and 
from  /S-naphiholmonosulphonic  acid  S.  The  color  is  sodium 
/-nitranilineazo-/5'-naphtholmonosulphonate.     Its  constitution   is 

probably : — 

N      = 


JNU, 


OBSERVATIONS    ON    ANIMALS.  121 

Typical  Reactions. — It  is  a  red-brown  powder,  producing  with 
water  an  orange-brown  solution.  This  solution  gives  with  sodium 
hydroxide  and  ammonium  hydroxide  a  fuchsin-red  color;  with 
copper  sulphate,  no  change ;  with  ammoniacal  copper  solution, 
a  red-violet  precipitate  soluble  to  the  same  color  in  ammonium 
hydroxide.  The  powder  dissolves  in  concentrated  sulphuric  acid 
to  a  bright  red  liquid  which  changes  to  orange-yellow  by  dilution 
with  water.  The  mode  of  formation  suggests  the  name,  parani- 
trazotin. 

A  rabbit  weighing  1500  grams  received  two  doses  of  2)^  grams 
each  by  the  oesophageal  tube  in  the  course  of  three  days.  It 
remained  lively.  Further  investigations  were  prevented  by  a 
want  of  material. 

Orange  II. 

This  color  is  also  known  as  orange  2,  /?-naphthol  orange, 
tropseolin  000  2,  mandarin,  mandarin  G  extra,  chrysaurin, 
and  golden  orange.  I  obtained  this  color  myself  from  /-diazo- 
benzensulphonic  acid  and  /9-naphthol.  It  crystallizes  from  water 
in  orange-yellow  plates.  It  is  azo-/5-naphthol-/-azobenzenesul- 
phonic  acid. 

N  =         N 


HO 


HSO3 

Wool  and  silk  are  colored  orange  in  an  acid  bath ;  cotton  only 
after  previous  mordanting. 

Typical  Reactions. — Orange-red  crystals  easily  soluble  in  water 
to  an  orange-red  solution.  The  watery  solution  gives  with  hydro- 
chloric acid  a  brownish  precipitate,  dissolving  in  alcohol  to  an 
orange-red  liquid.  Sodium  hydroxide  and  ammonium  hydroxide 
give  red-brown  solutions.  Ammoniacal  copper  solution  pro- 
duces a  gelatinous  red-brown  precipitate.  The  powder  dissolves 
in  concentrated  sulphuric  acid  to  a  fuchsin-red  liquid,  which,  on 
dilution  with  water,  gives  a  brownish-red  precipitate. 


122  THE    COAL-TAR   COLORS. 

Exp.  I. — Dog  weighing-  10500  grams  received,  July  4th,  5  grams 
by  the  tube.  Urine  red,  diarrhoea,  (?)  vomiting.  (?)  The  red  urine 
was  decolorized  by  warming  with  stanTious  chloride  and  hydrochloric 
acid.  July  5th,  no  administration.  Urine  colored  by  the  dye  stuff, 
vomiting  (?).  July  6th,  urine  red.  July  7th,  urine  weak  red  with 
much  sediment.  July  8th,  urine  scanty,  much  sediment.  July  9th  to 
1 2th,  urine  alkaline,  turbid,  contains  albumin.  July  13th,  7  grams  by 
the  tube.  July  14th,  urine  orange-red,  no  food  taken,  diarrhoea.  July 
15th,  animal  ate  little,  urine  weak  reddish.  July  17th,  2  grams  ad- 
ministered. No  food  taken ;  diarrhoea  ;  urine  neutral,  weak  red,  very 
turbid,  doubtful  traces  of  albumin.  July  i8th,  animal  very  miserable, 
eyelids  adherent.  July  19th,  no  administration,  animal  in  bad  con- 
dition. July  20th,  much  albumin  in  the  orange- colored  urine; 
animal  very  miserable;  40°  rectal  temperature.  July  27th,  animal 
very  weak  ;  urine  orange-red,  colored  dark  red  by  sodium  hydroxide  ; 
acid  turns  it  yellow.  Cotton  easily  dyed.  July  23d,  animal  found 
dead  in  its  cage.  July  24th,  post-mortem  showed  much  fatty  tissue 
of  normal  color,  muscles  normal  in  color,  stomach  and  intestines 
pale  ;  in  the  stomach  and  upper  section  of  the  intestines  numerous 
abscesses,  recent  and  just  cicatrizing;  liver  somewhat  fatty  degener- 
ated ;  kidneys  pale ;  epithehum  fatty ;  lungs  normal ;  heart  pale, 
containing  much  white  coagula  ;  brain  not  tinged. 

Exp.  2. — A  white  rabbit,  weighing  2250  grams,  died  within  twelve 
hours  after  the  administration  of  3  grams  of  the  color.  Four  hours 
after  the  administration  the  animal  was  running  about  the  room, 
lively.     Post-mortem  was,  through  accident,  omitted. 

Exp.  J, — Dog  weighing  4300  grams  received,  December  12th,  .5 
gram  dissolved  in  about  10  c.  c.  of  lukewarm  water,  injected  under 
the  skin  of  the  back.  December  12th  to  14th,  urine  alkaline,  some 
albumin,  no  sugar;  color  weak  orange.  December  15th,  no  abscess 
at  the  point  of  injection,  animal  lively  and  took  food.  December  i6th, 
.25  gram  subcutaneously  on  the  opposite  side  of  the  back.  Urine 
orange  red,  acid,  traces  of  albumin.  Wool  easily  dyed  in  the  liquid 
acidulated  with  sulphuric  acid.  Dec.  17th,  .5  gram  subcutaneously. 
No  abscesses,  some  diarrhoea.  Dec.  18th,  rectal  temperature  39.5°; 
right  eye  closed  and  inflamed ;  traces  of  albumin  ;  urine  strongly 
orange  ;  dyes  wool  easily.  Dec.  19th,  coryza  better,  but  cataract 
appearing.  .5  gram  administered  subcutaneously.  Urine  red 
orange;  animal  lively.  Dec.  20th,  no  injection;  little  albumin; 
animal   trembled.      Dec.  21st,  but  little  albumin.     .75    gram   given 


OBSERVATIONS    ON    ANIMALS.  1 23 

in  two  places  on  the  back.  Dec.  22d,  animal  very  miserable ; 
trembled  and  snarled  ;  but  little  albumin.  Dec.  23d,  continued  the 
same.  Dec.  25th,  abscesses  developed  at  the  point  of  injection  of 
Dec.  2 1  St.  Dec.  26th,  animal  livelier.  Dec.  27th,  abscesses  opened 
spontaneously  ;  animal  weighed  3840  grams,  having  lost,  therefore, 
460  grams  in  fifteen  days.  Jan.  2d,  abscesses  nearly  healed ;  animal 
hvely ;  took  food.  Jan.  3d,  animal  began  to  lose  hair.  Jan.  14th. 
almost  without  hair.  Weight,  3890  grams  ;  lively ;  ate  well.  Jan, 
17th,  slept  well,  ate  heartily.  Jan.  26th,  animal  had  completely 
recovered;  weight  5120  grams. 

/?-naphthol  orange  is,  therefore,  according  to  experiment 
I,  poisonous  in  small  doses  when  administered  by  the  stomach, 
and  suffices  to  kill  a  moderately  strong  dog.  The  rabbit,  experi- 
ment 2,  serves  as  a  control.  In  contrast  to  /3-naphthol  orange, 
Cazeneuve  and  Lepine  found  the  corresponding  a-naphthol 
orange,  distinguished  from  /?-naphthol  orange  only  by  the  posi- 
tion of  the  hydroxyl  group,  non-poisonous.  The  /3-color  seems 
almost  to  show  its  poisonous  action  when  administered  subcu- 
taneously,  but  the  animal  did  not  succumb  to  the  experiment. 

Ponceau  4  GB. 

This  color  is  also  known  as  croceln  and  brilliant  orange.  I 
prepared  this  color  myself  from  diazobenzene  chloride  and 
sodium  /9-naphtholsulphonate  S.  (Schasffer's  salt.)  It  has  prob- 
ably the  constitution : — 

N         =         N 


Typical  Reactions. — In  the  pure  condition  a  red  crystalline 
powder  that  dissolves  not  very  easily  in  water  to  a  red  solution 
which  produces,  with  hydrochloric  acid,  a  yellowish-brown  pre- 
cipitate, easily  soluble  to  yellowish-red  color  in  alcohol.  With 
sodium  hydroxide  and  ammonium  hydroxide,  a  yellow  solution. 
With  ammoniacal  copper  solution,  a  dirty,  yellowish-broAvn  pre- 
cipitate.    Concentrated  sulphuric  acid  dissolves  the  powder  to 


124  THE    COAL-TAR    COLORS. 

an  orange-yellow  liquid,  which  deposits  a  yellowish-brown  pre- 
cipitate when  diluted  with  water.  In  acid  solution,  wool  is  col- 
ored orange  yellow. 

Exp.  I. — Dog  weighing  12400  grams;  received,  June  19th,  2  grams 
dissolved  in  water  by  the  tube.  Urine  rose-colored.  June  20th,  2 
grams  administered.  Urine  reddish.  June  21st,  2  grams  in  water. 
Animal  lively  ;  urine  reddish,  no  blood,  no  albumin.  June  22d,  2 
grams.  Animal  lively  ;  urine  alkaline,  no  albumin,  no  phenol.  June 
23d,  4  grams.  Urine  normal  color,  alkaline,  turbid,  no  albumin. 
June  24th,  animal  lively,  took  food.  June  27th,  4  grams.  June  28th, 
urine  normal  color,  free  from  albumin. 

In  a  second  investigation  a  dog  weighing  8500  grams  received 
for  an  entire  month  i  gram  daily  by  the  cesophageal  tube. 
Urine  remained  uncolored,  animal  lively,  with  undisturbed 
appetite.  The  loss  of  weight,  200  grams  in  thirty  days,  need 
not  be  considered. 

This  color  can  be  regarded  as  non-poisonous. 

Archil-substitute.     Naphthion  red  (now  obsolete). 
This  color  is  prepared  from  diazotized^-nitraniline  and  naph- 
thionic  acid  and  has,  therefore,  the  constitution  : — 

N     =     n/\X    \ 


NO2 


My  preparation  was  obtained  from  the  Aniline  Manufacturing 
Company  of  Berlin.  It  was  in  the  form  of  a  red  liquid  which 
contained  8.2  per  cent,  of  the  color. 

Typical  Reactions. — The  color  has  the  form  of  a  brown  paste 
soluble  in  water  to  a  red-brown  color,  which  solution  gives  with 
hydrochloric  acid  a  bluish-red  precipitate  which  is  soluble  in 
water  and  in  96  per  cent,  alcohol  to  a  red  brown.  Acetic  acid 
produces  a  reddish-brown  solution.  Sodium  hydroxide  produces 
a  bluish-red  precipitate   difficultly  soluble   in   water  but    easily 


OBSERVATIONS    ON    ANIMALS.  I25 

soluble  in  alcohol  to  a  brownish-red  liquid.  Ammonium  hy- 
droxide produces  a  brownish-red  solution.  Ammoniacal  copper 
solution  produces  a  dirty  red  precipitate  which  is  soluble  in  hot 
water.  The  paste  dissolves  in  concentrated  sulphuric  acid  to  a 
fuchsin-red  solution,  which,  on  dilution  with  water,  gives  a  red- 
brown  precipitate.  It  colors  wool,  in  acid  solution,  archil 
red. 

Exp.  I. — December  24th  and  26th,  dog  weighing  3810  grams, 
urine  weakly  alkaline,  some  albumin,  no  mucin.  Dec.  27th,  20  c.c. 
of  the  solution  equals  1.64  grams  of  the  color  administered  with  pep- 
tone. Tendency  to  vomit,  but  no  actual  vomiting.  Urine  normal, 
nearly  colorless,  slightly  alkaline,  traces  of  albumin.  No  character- 
istic changes  with  acids  or  alkalies,  or  concentrated  sulphuric  acid. 
Dec.  28th,  20  c.c.  of  the  solution  with  peptone.  Urine  as  above, 
animal  lively.  Dec.  30th,  40  c.c.  of  the  solution  equals  3.28  grams  of 
the  color.  Dec.  31st,  animal  lively,  took  food;  urine  as  above; 
weight  3980  grams,  consequently  a  gain  of  170  grams  in  seven  days, 
Jan.  1st,  1889,  urine  uncolored,  some  albumin,  much  sulphates.  Jan. 
2d,  50  c.c.  of  the  solution  equals  4.1  grams  of  the  color.  Urine  alka- 
line, otherwise,  as  above,  no  color.  Jan.  3d,  urine  gives  a  rose  color 
to  filter  paper  ;  alkaline,  with  very  little  albumin,  dyes  wool  when 
acidified  ;  animal  lively  ;  experiment  relinquished. 

In  a  second  investigation,  a  dog  weighing  4500  grams  received 
daily  for  one  month  10  c.c.  of  the  color  solution,  which  equals 
.82  gram  of  the  color, — therefore,  altogether,  24  grams,  which 
showed  the  same  results  as  experiment  No.  i,  except  that  the 
urine  remained  uncolored. 

Exp.  2. — Dog  weighing  4980  grams,  on  Jan.  2d  showed  urine  oi 
normal  color,  very  little  albumin,  and  received  10  c.c.  of  the  color 
subcutaneously,  which  equals  .82  gram,  of  the  color.  Jan.  3d,  urine 
reddish,  no  injection.  Jan.  4th,  urine  reddish,  traces  of  albumin. 
10  c.c.  of  the  solution  administered  on  left  side  of  the  back.  Jan.  5th, 
urine  reddish,  hardly  any  albumin,  much  sulphates  ;  animal  lively, 
no  abscesses.  Jan.  6th  to  7th,  no  abscesses,  animal  lively ;  little 
albumin.  Jan.  Sth,  animal  normal ;  urine  uncolored  ;  little  albumin. 
Jan.  9th,  food  taken;  no  abscesses;  20  c.c.  (equals  1.64  grams) 
injected  in  two  places  on  the  back.     Jan.  loth,  no  food  taken  ;   con- 


126  THE    COAL-TAR   COLORS. 

junctiva  not  colored;  urine  reddish;  no  albumin.  Jan.  nth,  no 
abscesses  ;  urine  uncolored,  little  albumin.  Jan.  12th,  urine  colorless, 
little  albumin.  Jan.  14th,  weight  4950  grams,  therefore,  no  reduction 
in  weight  in  twelve  days;  animal  lively,  no  abscesses.  Jan  17th, 
animal  lively  ;  very  little  albumin. 

This  color,  in  the  doses  indicated,  must  be  regarded  as  not 
poisonous  when  administered  by  the  stomach  or  subcutaneously, 
in  spite  of  the  fact  that  it  contains  a  nitro-group.  Probably,  as 
is  the  case  with  naphthol  yellow,  the  action  of  the  nitro-group 
is  ameliorated  by  the  simultaneous  presence  of  a  sulphonic 
group. 

Chrysoidin. 

This  color  is  prepared  from  diazobenzene  chloride  and  7?i- 
-diaraidobenzene,  and  has,  therefore,  probably,  the  constitution  : 

N  =  N 

^  NH2HCI 


NH2 

It  colors  wool  and  silk  without  a  mordant,  and  cotton  after 
mordanting,  orange.  My  specimen  was  obtained  from  the  Ani- 
line Manufacturing  Company  of  Berlin,  and  was  in  the  form  of  a 
reddish-brown  crystalline  powder  easily  soluble  in  water  to  a 
brownish-red  liquid. 

Typical  Reactions. — The  watery  solution  produces  with  hydro- 
chloric acid  a  brown  gelatinous  precipitate  easily  soluble  in  water 
to  an  orange-yellow  liquid.  Acetic  acid  produced  no  change. 
Sodium  hydroxide  and  ammonium  hydroxide  produced  orange- 
brown  precipitates  difficultly  soluble  in  water,  easily  in  alcohol, 
to  orange-yellow  liquids.  Ammoniacal  copper  solution  produced 
a  brownish-red  precipitate  soluble  in  hot  water  and  insoluble  in 
alcohol.  The  powder  dissolved  in  concentrated  sulphuric  acid 
to  a  yellowish-brown  liquid  which  by  dilution  with  water  became 
ponceaux. 

Exp.  I. — March  24th  and  25th,  dog  weighing  26600  grams.  Urine 
uncolored,  containing  albumin.     March  25th  to  26th,  3  grams  by  the 


OBSERVATIONS    ON    ANIMALS.  I  27 

tube.  March  26th  to  27th,  urine  colored  strongly  orange-brown  ;  albu- 
min distinctly  present.  March  29th  to  30th,  urine  slightly  colored, 
animal  lively.  April  ist,  10  grams  by  the  tube.  April  2d  to  5th, 
urine  colored  very  strong  brown;  little  albumin.  April  6th  to  7th, 
10  grams  administered.  Animal  took  food,  did  not  vomit.  April  8th 
to  loth,  urine  dark  brown,  albumin  distinct. 

In  a  second  investigation,  a  dog  weighing  9500  grams  took 
daily,  for  one  month,  i  grain  of  chrysoidin.  Animal  remained 
lively ;  urine  uncolored  and  free  from  albumin.  It  lost  during 
this  time  about  1200  grams,  therefore  about  one-eighth  of  its 
body  weight. 

Exp. 3. — April  I2th,  dog  weighing  58500  grams;  urine  uncolored, 
and  traces  of  albumin  present.  April  13th  to  14th,  .1  gram  subcutane- 
ously  in  10  c.c.  of  sterilized  water.  April  15th  to  27th,  urine  uncol- 
ored, little  albumin  ;  animal  hvely  ;  appetite  as  usual.  April  29th  to 
30th,  .1  gram  subcutaneously.  May  2d  to  3d,  animal  lively;  urine 
uncolored.  May  5th,  urine  uncolored  ;  very  little  albumin.  May  8th, 
.1  gram  subcutaneously.  May  loth,  urine  normal;  no  abscesses; 
appetite  good  ;  weight  4620  grams  ;  therefore,  lost  about  1230  grams, 
or  one-fifth  its  body  weight.  May  5th,  animal  normal ;  ate  well ; 
urine  nearly  free  from  albumin. 

hijection  mto  the  abdominal  cavity. — Dog  weighing  4500  grams  re- 
ceived, three  times  in  the  course  of  10  days,  .1  gram  of  chrysoidin  in 
sterihzed  water  injected  into  the  abdominal  cavity  with  a  sterilized 
syringe.  The  urine  remained  uncolored,  but  contained  some  albu- 
min. The  animal,  three  weeks  after  termination  of  the  experiment, 
was  entirely  well  and  had  good  appetite. 

Chrysoidin  produces,  according  to  my  investigations,  a  slight 
albuminuria  and  notable  reduction  of  the  body-weight,  but  fur- 
ther disturbance  has  not  been  noted.  With  large  doses  intro- 
duced into  the  stomach,  a  portion  of  the  color  appears  in  the 
urine.  In  contrast  to  the  experiment  with  dogs,  Blaschko 
describes  a  frequently  occurring  eczema  among  workmen  engaged 
in  the  manufacture  of  the  color.  To  determine  if  this  skin 
affection  is  caused  by  the  color  itself,  or  rather  by  the  materials 
required  for  its  manufacture  (especially  the  ;;/-diamidobenzene 
might  be  suspected)  requires,  I  think,  further  investigation. 


128  THE    COAL-TAR   COLORS. 

Diphenylamine  Orange. 
This  color,  known  also  as  acid  yellow  D,  diphenyl  orange, 
orange  IV,  tropaeolin  00,  orange  B,  aniline  yellow,  orange  G  S., 
new  yellow,  helioxanthin  (?),  is  produced  from  diazotized 
/-amidobenzenesulphonic  acid  and  diphenylamine.  The  com- 
mercial article  has  probably  the  following  constitution  : — 

N         =         N 


NaSOg  NH 

It  is  sodium  azodiphenylamine-/-azobenzenesulphonate.  The 
specimen  I  used  was  obtained  from  the  Aniline  Manufacturing 
Company  of  Berlin,  and  was  an  orange-yellow  powder  dissolv- 
ing in  cold  water,  but  not  very  easily,  to  an  orange-red  liquid. 

Typical  Reactions. — The  watery  solution  produced  with  hydro- 
chloric  acid  a  reddish-violet  precipitate  which  was  difficultly 
soluble  in  water,  but  easily  soluble  in  96  per  cent,  alcohol  and 
produced  an  orange-red  liquid.  Sodium  hydroxide  produced  a 
yolk-of-egg  color  and  dissolved  with  difficulty  in  water  to  the 
same  color;  in  96  per  cent,  alcohol,  to  an  orange-yellow  color. 
Ammonium  produced  an  orange  precipitate  tolerably  easily  solu- 
ble in  excess  of  the  precipitants.  Ammoniacal  copper  solution 
produced  a  yellow  precipitate  which  dissolved  in  hot  water  to  a 
brown  liquid  and  reprecipitated  on  cooling.  The  powder  dis- 
solves in  concentrated  sulphuric  acid  to  a  bluish-violet  solution 
which  on  dilution  with  water  gives  a  violet  precipitate  that  is 
soluble  in  excess  of  water  to  a  reddish-violet  liquid.  In  acid 
solution  wool  is  colored  orange-yellow.  The  color  serves  as  an 
indicator  in  titration,  since  in  the  presence  of  small  amounts  of 
free  acid,  except  carbonic,  it  is  changed  to  red. 

Exp.  I. — January  i6th-i8th,  dog  weighing  27350  grams;  little 
albumin  in  urine.  January  19th,  5  grams  in  peptone  by  the  tube. 
Urine  on  standing  became  dark  colored  from  the  surface  downward  ; 
albumin  present,  sulphates  abundant,  reaction  alkaline  ;  animal  was 


OBSERVATIONS    ON    ANIMALS.  1 29 

lively  and  took  food.  January  20th,  urine  almost  black,  otherwise  as 
the  day  before.  January  21st,  5  grams  administered.  Urine  alkahne, 
almost  black.  When  treated  with  strong  hydrochloric  acid  and  dis- 
tilled, it  gives  only  traces  of  phenol.  The  original  urine  gives  with  fer- 
ric chloride  no  characteristic  reaction.  Addition  of  hydrochloric  acid 
produces  a  flocculent  precipitate  insoluble  in  water,  but  soluble  in  hot 
alcohol.  The  filtrate  from  the  acidulated  urine  gives  a  distinct  albu- 
min reaction.  January  23d,  the  substance  precipitable  by  the  addi- 
tion of  acid  was  no  longer  present ;  albumin  abundant,  3  grams  ad- 
ministered. January  24th,  precipitable  substance  still  missing  ;  urine 
almost  colorless;  albumin  scanty.  January  25th,  urine  very  dark, 
gives  precipitate  with  hydrochloric  acid ;  albumin  scanty.  January 
26th,  urine  uncolored,  albumin  scanty.  January  27th,  same.  Janu- 
ary 28th,  10  grams  administered;  urine  abundant,  strongly  black, 
contains  albumin  and  sulphates,  alkahne.  January  29th  and  30th, 
urine  dark  colored,  albumin  abundant ;  very  little  food  taken.  Janu- 
ary 31st,  much  albumin  ;  weight,  2635  grams  ;  therefore,  1000  grams 
lost, — that  is  to  say,  1-27  of  the  body  weight  in  fourteen  days.  Feb- 
ruary 2d,  fifteen  grams  administered ;  urine  deep  color ;  albumin 
abundant ;  animal  lively.  February  3d,  urine  dark  brown  ;  albumin 
distinct ;  appetite  good.  February  7th,  urine  almost  normal  in  color  ; 
animal  lively. 

Exp.  2. — January  15th  to  i8th,  dog  weighing  9730  grams,  showing 
but  little  albumin  in  the  urine.  January  19th,  3  grams  in  peptone. 
January  21st,  3  grams.  January  22d,  no  administration  ;  animal  lively. 
January  23d,  2  grams  ;  food  taken.  January  27th,  animal  lively,  took 
food ;  3  grams  of  the  color  administered.  January  28th  to  30th,  3 
grams  each  day  ;  animal  lively.  January  31st,  3  grams,  animal  took 
food  and  was  lively  ;  weight,  9820  grams.  Animal  received,  from 
February  2d  to  15th,  daily,  3  grams  ;  urine  contained  unchanged  color 
and  albumin  ;  animal  remained  lively. 

Exp.  J. — March  20th,  dog  weighing  5450  grams  ;  albumin  dis- 
tinctly present.  March  21st  to  22d,  urine  colorless,  contained  distinct 
amount  of  albumin ;  ,1  gram  administered  subcutaneously.  March 
22d  to  23d,  no  abscesses  ;  urine  uncolored  ;  animal  lively.  March 
24th,  .1  gram  subcutaneously  ;  urine  uncolored,  little  albumin.  March 
25th,  urine  uncolored,  contained  but  httle  albumin  ;  exhibited  no 
change  on  addition  of  hydrochloric  acid  or  sodium  hydroxide. 
March  26th,  no  abscess  ;  animal  took  food.  March  29th  to  30th,  no 
abscesses,  urine  uncolored.  March  31st  to  April  4th,  .1  gram  sub- 
II 


130  THE    COAL-TAR    COLORS. 

cutaneously  ;  took  food.  April  4th,  animal  lively ;  weight,  5220 
grams  ;  therefore,  lost  230  grams  in  fourteen  days,  or  1-24  of  the  body 
weight.     April  12th,  no  abscesses;  animal  lively. 

According  to  the  above  investigations,  diphenylamine  orange 
causes  albuminuria,  but  further  disturbances  did  not  appear  dur- 
ing the  several  weeks'  observations  on  the  animals  used. 

Metanil  Yellow. 

This  color,  also  known  as  orange  MN,  is  produced  by  diazo- 
tizing  w-amidobenzenesulphonic  acid  and  the  conjugation  of  the 
resulting  compound  with  diphenylamine.  It  has,  therefore, 
probably,  the  constitution  :  — 

N         =-  N 

/X       /\       /X 

NaSO 


3 

^  ^       NH 


The  commercial  form  is  the  sodium  azodiphenylamine-;^/- 
azobenzenesulphonate.  My  specimen  was  obtained  from  the 
Aniline  Manufacturing  Company,  of  Berlin,  and  exhibited  the 
form  of  a  yellowish-brown  powder,  smelling  strongly  of  diphe- 
nylamine. 

Typical  Reactions. — It  dissolves  in  water  to  a  yellowish  solu- 
tion. Hydrochloric  acid  produced  a  violet  precipitate,  which 
slowly  dissolved  to  a  fuchsin-red  liquid  in  an  excess  of  hydro- 
chloric acid  or  water.  Sodium  hydroxide  does  not  immediately 
affect  the  watery  solution.  In  time  a  yellow  crystalline  precipi- 
tate separates,  which  is  soluble  in  warm  water  to  an  orange-red 
liquid.  The  dried  color  dissolves  in  concentrated  sulphuric  acid 
to  a  violet  solution,  which  is  changed  to  a  fuchsin  red  by  dilu- 
tion with  water.  Ammoniacal  copper  solution  produces,  in 
watery  solution,  a  heavy,  flocculent,  pale-yellow  precipitate  diffi- 
cultly soluble  in  water. 

For  purification  the  color  was  dissolved  in  water,  filtered,  and 
separated  by  the  addition  of  sodium  acetate.     The  yellow  mass 


OBSERVATIONS    ON    ANIMALS. 


131 


was  freed  from  the  adherent  licjuid  by  the  filter  pump  and  dis- 
solved in  hot  alcohol,  in  which  it  is  difficultly  soluble,  and  ob- 
tained from  this  in  the  form  of  yellow  crystals.  The  material 
used  for  the  experiments  was  almost  pure,  as  the  following  ana- 
lytical statement  shows  :  0.4895  gram  of  the  color  dried  in  105° 
gave  0.084  sodium  sulphate.  Sodium,  required,  6.1  ;  found,  5.6. 
Like  diphenylamine  orange,  this  color,  in  acidified  solution, 
dyes  wool  orange-yellow. 

Exp.  I. — Dog  weighing  11600  grams.  April  2d,  urine  almost 
free  from  albumin.  April  4th,  10  grams  by  the  tube  ;  animal  vomited 
and  did  not  take  food.  April  5th,  10  grams  ;  animal  vomited  and 
did  not  take  food.  April  7th,  animal  very  miserable  and  did  not 
take  food  ;  labored  respirations.  April  8th,  died  during  the  night 
of  the  7th  day.  Post-mortem  : — Body  stiff,  skin  not  colored,  mucous 
membrane  yellowish,  intestines  pale,  not  stained ;  kidneys  pale,  not 
stained  ;  liver  red,  contained  much  unchanged  color  since  it  becomes 
red  with  concentrated  sulphuric  acid  ;  much  unchanged  color  in  the 
stomach  ;  lungs  contained  a  circumscribed  focus  in  which  tubercle 
bacilli  were  recognizable,  but  were  otherwise  normal.  The  deposit 
was  on  the  anterior  surface  of  the  lower  lobe  of  the  right  lung.  The 
animal  took,  in  the  course  of  four  days,  20  grams  of  the  color,  there- 
fore, 1.7  grams  per  kilo  of  the  body  weight,  and  was  killed  by  this 
dose. 

Exp.  2. — March  19th,  dog  weighing  11250  grams.  Albumin  dis- 
tinctly present.  March  21st,  i  gram.  Urine  colorless,  albumin 
distinct.  March  22d,  urine  colorless,  developed  dark  color  from  the 
surface  ;  albumin  distinct.  March  25th,  urine  in  thin  layers,  orange- 
yellow,  became  bluish-violet  with  hydrochloric  acid,  and  orange-red 
with  sodium  hydroxide.  Animal  lively ;  conjunctiva  not  tinged. 
March  26th,  10  grams.  About  one  hour  after  the  administration 
strong  vomiting  occurred.  March  27th,  very  little  food  taken  ;  urine 
dirty  greenish  yellow.  March  28th  to  29th,  urine  normal  in  color, 
albumin  distinct.  April  ist,  5  grams  administered.  Animal  took 
little  food  and  died  on  the  night  of  April  ist.  Weight  8750  grams. 
Post-mortem ;  skin  and  subcutaneous  cellular  tissue,  serous  membranes 
and  intestines,  and  contents  of  intestines  yellow.  Intestinal  contents 
became  colored  ruby-red  with  concentrated  sulphuric  acid,  and  there- 
fore, contained  the  unchanged  color.  The  liver  was  hyperasmic, 
dark  red,  and  gave  the  reaction  with  concentrated  sulphuric  acid. 


132  THE    COAL-TAR   COLORS. 

Kidneys  were  deep  yellow  ;  conjunctiva  yellow.  Contents  of  the 
bladder  were  orange-yellow  and  were  turned  red  by  concentrated 
sulphuric  acid,  and  contained,  therefore,  the  unchanged  color. 

This  animal  received  in  the  course  of  twelve  days  twenty-one 
grams  of  the  color,  or  0.53  gram  per  kilo  of  the  body  weight. 
This  dose  is  fatal. 

Exp.  J. — Dog  weighing  5220,  grams,  on  April  3d,  had  traces  of 
albumin  in  the  urine.  April  6th,  .1  gram  in  10  c.c.  of  sterilized 
water  administered  subcutaneously.  Animal  trembled  a  great  deal. 
April  9th,  .15  gram  subcutaneously  at  two  points.  Animal  trembled, 
but  ate  freely.  April  nth,  .15  gram.  No  abscesses,  animal  livelier, 
trembling  no  longer  observed  :  urine  contained  traces  of  albumin. 
April  14th,  weighed  4790  grams,  was  lively  and  took  food. 

Metanil  yellow  must  be  considered  poisonous  when  admin- 
istered by  the  stomach,  from  the  indication  of  Experiments  i 
and  2.  The  lethal  dose,  which  is  determined  by  Experiment 
2,  is  0.53  gram  per  kilo  of  the  body-weight.  The  isomeric 
diphenylamine  orange  is,  on  the  other  hand,  non-poisonous. 

Azarin  S. 

Azarin  S  is  obtained  by  the  diazotizing  of  amidodichlor- 
phenol,  joining  the  compound  with  /?-naphthol,  and  treating  the 
resulting  color  with  ammonium  acid  sulphite.  The  operation, 
therefore,  takes  place  in  two  steps  :  one,  the  production  of  the 
azo-color;  secondly,  addition  of  the  ammonium  acid  sulphite. 
For  the  product  of  this  reaction,  the  following  formula  is  gener- 
ally assumed.* 

CI2 
CeH^HO 

NH  —  NCioHgHO 
NH4SO3 

The  color  itself  is  insoluble,  but  becomes  soluble  through  the 
addition  of  the  acid  sulphite.  If  the  azarin  S  so  prepared  is 
printed  together  with  aluminum  acetate  on  cotton  goods,  and 

^  [The  formula  for  azarin  is  given  differently  by  different  authorities. — 
Trans.] 


OBSERVATIONS    ON    ANIMALS.  1 33 

the  fabric  treated  •  with  warm  water  in  the  presence  of  an 
alkali  or  an  acid,  the  material  is  split  up  into  a  soluble  sul- 
phite, or  free  sulphurous  acid,  and  an  insoluble  dichloramido- 
phenolazo-/5-naphthol.  The  latter  is  fixed  upon  the  fibre  as  a  color. 
My  preparation,  for  which  I  am  indebted  to  the  kindness  of  Mr. 
V.  Gerichten,  was  manufactured  by  Meister,  Lucius  &  Briining. 
It  was  a  thin,  yellowish  orange,  strongly  acid  paste,  smelling  of 
sulphurous  acid.     It  was  not  entirely  soluble  in  water. 

Typical  Reactions. — The  watery  solution  produced  with  hydro- 
chloric acid  a  yellow  precipitate  which  dissolved  in  alcohol  with 
a  yellow  color.  Ammonium  hydroxide  produced  a  brown-red 
solution  :  sodium  hydroxide,  a  bluish-violet  solution,  which  by 
warming  became  reddish-violet  and  retained  this  color  on  cool- 
ing. Concentrated  sulphuric  acid  produced  a  dark-red  solution, 
sulphurous  acid  escaping.  On  diluting  the  solution  with  water  a 
brown  solution  appeared  which  was  easily  soluble  in  alcohol  to 
a  brown  color.  Ammoniacal  copper  solution  produced  a  violet 
precipitate  appearing  in  thin  layers  as  reddish. 

Exp.  I. — A  large  dog  weighing  25600  grams  received,  in  the  course 
of  twenty-five  days,  a  total  of  thirty-five  grams  of  the  color  suspended 
in  water  administered  by  the  tube.  The  urine  was  colored  a  weak 
yellow  and  contained  a  distinct  amount  of  albumin.  Sulphurous  acid 
was  produced  on  adding  hydrochloric  acid  to  the  urine.  The  appe- 
tite of  the  animal  was  not  diminished.  In  a  second  experiment,  a  dog 
weighing  10,300  received,  in  the  course  of  twenty  days,  twenty  grams 
of  the  color  administered  in  the  same  manner.  Results  the  same 
as  in  experiment  i. 

Exp.  3. — A  dog  weighing  4700  grams  received,  in  the  course  of  eight 
days,  three  injections  of  i  gram  each  of  the  azarin  paste  suspended  in 
IOC.  c.  of  water  inserted  under  the  skin  of  the  back.  During  the 
period  of  observation  (three  weeks)  no  abscess  appeared  at  the  point 
of  injection,  nor  was  there  albumin  or  abnormal  coloring  matter  found 
in  the  urine.     The  appetite  was  unimpaired. 

Another  dog  received,  on  May  15th,  5  c.c.  of  the  paste  in  5 
c.c.  of  sterilized  water,  therefore  altogether  10  c.c.  of  liquid, 
which  was  injected  by  means  of  the  Koch  syringe  into  the  ab- 
dominal cavity.     On  the  following  day  the  animal  had  no  appe- 


134  THE    COAL-TAR   COLORS. 

tite,  but  the  urine  remained  uncolored.  On  the  third  day  the 
animal  seemed  very  miserable  and  took  no  food.  There  was  a 
little  albumin  in  the  urine.  The  day  after,  the  animal  was  found 
dead  in  its  cage.  Post-mortem  showed  the  peritoneum  and  the 
inner  surface  of  the  intestines  tinged  in  spots  with  a  red  color. 
The  small  intestines  were  adherent  for  a  considerable  distance  to 
the  peritoneum.  The  cause  of  death  was  considered  to  be  peri- 
tonitis without  effusion.  The  result  of  this  post-mortem  is  of 
much  interest.  The  red  spots  consisted,  as  was  determined  by 
chemical  analysis,  of  the  azo-color,  which  is  the  basis  of  the 
azarin  S.  Consequently,  in  the  peritoneal  cavity  the  same 
splitting  up  of  the  azarin  S  had  occurred  which  takes  place 
when  it  is  attached  to  textiles. 

Administered  by  the  stomach,  the  azarin  S  is  harmless. 

DISAZO-COLORS. 

The  following  is  a  summary  of  the  results  obtained  \^th  the 
disazo-colors  submitted  to  test  by  me,  viz  : — Fast  brown  G, 
woolblack,  naphthol  black  P,  Congo  red,  azo-blue,  chrysamine 
R. 

All  these  proved  to  be  non-poisonous,  except  that  naphthol 
black  P  had  an  injurious  effect  when  administered  subcutane- 
ously. 

PRIMARY  DISAZO-COLORS. 
Fast  Brown  G. 
This  color  is  produced  by  diazotizing  two  molecules  of/-amido- 
benzenesulphonicacid  and  joining  a  molecule  of  a-naphthol.  It 
has  the  constitution  : — 

NaSO.,  NaSOa 


N=N       N=N 

I I 

C,oH,HO 

It  is  sodium  a-naphtholdisazo-/-azobenzenesulphonate.     The 


PRIMARY    DISAZO-COLORS.  1 35 

specimen  I  employed  was  obtained    from   the  Aniline    Manu- 
facturing Company  of  Berlin. 

Typical  Eeactions. — A  brown  powder  producing  a  red-brown 
solution  in  water,  which  gives  with  strong  hydrochloric  acid  a 
violet  precipitate,  dissolving  to  a  violet  solution  in  hydrochloric 
acid,  and  in  water  to  a  brown  solution.  Sodium  hydroxide  and 
ammonium  hydroxide  produce  a  cherry-red  liquid.  Ammoniacal 
copper  solution  produces  in  concentrated  solution  a  cherry-red 
precipitate  easily  soluble  in  water.  The  powder  dissolves  in 
concentrated  sulphuric  acid  to  a  red-violet  liquid  which  turns 
violet-yellow  on  boiling.  The  reddish-violet  liquid,  on  being 
diluted  with  water,  turns  cherry-red. 

Exp.  I. — Dog  weighing  9630  grams,  showing  but  litde  albumin  in 
the  urine,  received  on  January  19th  three  grams  by  the  tube.  January 
20th,  urine  contained  but  little  albumin  and  was  almost  normal  in 
color ;  addition  of  sodium  hydroxide  produced  a  bluish-red  color  ; 
therefore,  traces  of  the  administered  color  were  present.  The  urine, 
acidulated  with  acetic  acid,  dyed  wool  red-brown.  January  21st,  three 
grams  given.  January  22d,  diarrhoea;  urine  red  but  not  bloody; 
albumin  slight ;  sodium  hydroxide  produces  a  bluish-red  color,  and 
the  urine,  acidulated  with  acetic  acid,  easily  dyes  yarn.  January  23d, 
urine  but  little  colored,  becomes  a  weak  bluish-red  with  sodium, 
hydroxide  ;  two  grams  administered.  January  24th,  urine  strongly  red, 
little  albumin.  January  25th,  urine  normal  in  color,  traces  of  albumin. 
January  26th  to  29th,  urine  normal  in  color,  traces  of  albumin, 
January  30th,  urine  almost  free  from  albumin  ;  five  grams  administered 
January  31st,  marked  diarrhoea;  urine  hardly  colored,  and  gives 
with  sodium  hydroxide  a  weak  fuchsin  red,  little  albumin  ;  weight, 
8820  grams.  February  3d,  ten  grams  of  the  color  administered. 
February  4th,  severe  diarrhoea ;  urine  contained  unchanged  color ; 
animal  did  not  take  food.  February  5th,  urine  same  as  day  before. 
February  7th,  urine  colorless  ;  little  albumin  ;  diarrhoea  ;  some  food 
taken.     February  12th,  animal  normal;  albumin  slight. 

In  a  second  experiment  a  dog  weighing  5900  grams  received 
during  an  entire  month,  daily,  two  grams  of  the  color.  After 
six  days  a  slight  diarrhoea  was  produced,  which  continued  almost 
during  the  month.  Appetite  was  diminished,  and  there  was  lost 
about  one-fifth  of  the  original  weight. 


136  THE    COAL-TAR    COLORS. 

According  to  these  experiments  this  color  in  continuous,  though 
slight,  doses,  or  in  larger  doses,  but  less  frequently,  produces 
diarrhoea,  anorexia,  and  emaciation. 

Exp.  J. — A  dog  weighing  6730  grams,  not  showing  any  albumin- 
uria, received  on  March  5th  o.i  gram  of  the  color  in  10  c.  c.  of  luke- 
warm water  subcutaneously.  Urine  was  uncolored  and  contained 
little  albumin.  March  6th,  no  abscess ;  urine  uncolored,  no  albumin  ; 
condition  continued  the  same  up  to  March  12th,  when  o.i  gram  was 
administered  subcutaneously;  March  13th,  no  abscess.  March  14th, 
O.I  gram  subcutaneously;  animal  continued  lively  and  took  food. 
March  14th  to  i8th,  no  abscess  ;  urine  uncolored,  no  albumin.  March 
20th,  animal  lively ;  weight,  6450  grams.  March  23d,  no  abscess ; 
urine  almost  uncolored,  and  albumin  slight ;  no  change  with  sodium 
hydroxide  or  hydrochloric  acid.  March  26th,  0.1  gram  subcutan- 
eously.    March  28th  to  April  loth,  animal  lively  ;  no  abscess. 

Repeated  doses  of  .1  gram  subcutaneously  did  not  unfavorably 
affect  the  health  of  the  animal. 

SECONDARY  DISAZO-COLORS. 

Wool   Black. 

This  color  is  produced  by  the  action  of  diazotized  amidoazo- 
benzenedisulphonic  acid  on  /-tolyl-/S-amidonaphthalene,  and  has 
the  following  formula  : — 

C6H^(NaS03)N  =  NCgH3(NaS03)N  =  NCioH6(NH)(CH3)CeH^. 

It  may  be  termed  sodium /-tolyl-/5-amidonaphthalene-azoami- 
doazobenzenedisulphonate.  The  specimen  I  used  was  from 
the  Aniline  Manufacturing  Company  of  Berlin. 

Typical  Reactions. — Dark-blue  powder  producing  bluish-violet 
in  water,  which  gives  with  hydrochloric  acid  a  reddish-violet 
precipitate  soluble  in  water.  Ammonium  hydroxide  gives  a 
bluish-violet  solution.  With  ammoniacal  copper  solution,  a 
bluish-violet  precipitate  difficultly  soluble  in  water.  The  powder 
dissolves  in  concentrated  sulphuric  acid  to  a  blue  solution  which 
gives  a  brown  precipitate  on  dilution  with  water  :  this  is  decom- 
posed on  boiling.  By  boiling  with  dilute  sulphuric  acid  the 
wool-black,  according  to  Witt,  is  decomposed  to  tolunaphtazin 


SECONDARY   DISAZO  COLORS.  1 37 

and  amidoazobenzenedisulphonic  acid.  The  color  in  acid  bath 
dyes  wool  bluish  black. 

'  Exp.  I. — Dog  weighing  29940  grams,  showing  a  weak  alkaline 
urine,  with  little  albumin,  received,  December  28th,  5  grams  of  the 
color  in  peptone,  by  the  tube.  The  urine  remained  normal  color,  was 
neutral,  contained  a  little  albumin,  much  sulphates,  and  produced 
with  acids  and  alkalies,  even  on  boiling  with  concentrated  sulphuric 
and  hydrochloric  acids,  no  characteristic  reaction.  December  29th, 
5  grams  of  the  color  administered.  Animal  remained  lively  ;  urine 
normal  in  color.  December  30th,  five  grams  of  the  color  admin- 
istered. Urine  normal  in  color,  animal  lively  ;  albumin  and  sulphates 
as  before.  Dec.  31st  to  Jan.  ist,  urine  uncolored.  Jan.  2d,  ten 
grams  by  the  tube  ;  urine  intensely  dark  blue,  in  thick  layers  black  ; 
acidified,  it  colors  wool  bluish-black;  it  contained  albumin,  as  was 
demonstrated  after  precipitation  and  filtration  from  the  color.  Jan. 
4th,  urine  colorless,  contained  very  little  albumin.  Ten  grams  ad- 
ministered. Jan.  5th,  urine  intensely  dark  blue  ;  in  thick  layers, 
almost  black.  The  color  was  separated  from  the  urine  by  the 
addition  of  sodium  acetate.  Jan.  6th  to  7th,  animal  took  food ;  urine 
colorless,  darkened  from  the  surface  downward  on  standing  ;  reaction 
alkaline;  albumin  distinct,  sulphates  abundant.  Jan,  7th  to  12th, 
animal  lively.  Jan.  13th  to  19th,  albumin  distinctly  present;  animal 
lively  ;  appetite  good.     Jan.  20th,  albumin  slight. 

Exp.  2. — Dog  weighing  3520  grams,  urine  of  which  was  colorless 
and  free  from  albumin,  received,  Jan.  21st,  .25  gram  of  the  color  in 
10  c.c.  of  lukewarm  water  under  the  skin  of  the  back.  Jan.  22d, 
rectal  temperature  39.5°;  urine  uncolored;  no  abscess;  animal 
lively  and  took  food.  Jan.  23d,  .25  gram  administered;  animal 
lively ;  no  abscess.  Jan.  24th,  .25  gram  administered.  Urine  uncol- 
ored ;  traces  of  albumin.  Jan.  26th  to  27th,  urine  uncolored,  tem- 
perature normal.  Jan.  28th,  abscess  on  the  right  side  of  the  back  ; 
0.25  gram  administered  subcutaneously.  Jan.  29th,  urine  colorless, 
little  albumin.  Jan.  30th,  urine  colorless,  alkaline,  little  albumin  ; 
abscess  reduced  in  extent. 

Wool  black  is  non-poisonous  both  by  gastric  and  by  subcuta- 
neous administration. 
12 


138  THE   COAL-TAR   COLORS. 

Naphthol  Black  P. 

This  color  is  produced  by  the  diazotizing  /S'-amidonaphtha- 
lenedisulphonic  acid  G,  and  conjugation  with  a-amidonaph- 
thalene.  The  a-azoamidonaphthalene-/5-amidonaphthalenedi- 
sulphonic  acid  thus  produced  is  diazotized  again  and  united  to 
/5-naphtholdisulphonic  acid  (R-salt). 

According  to  this  synthesis  the  color  has  the  following 
formula : — 

C,oH5(NaS03)N  z.^  NqoHgN  =  NCioH^(NaS03)2HO. 

and  is  the  sodium  amidoazonaphthalenedisulphonateazo-/?- 
naphtholdisulphonate  R.  I  am  indebted  to  the  firm  of  L. 
Cassella&  Co.,  of  Frank,  o.  M.  for  the  specimens  I  used.  Like 
wool  black,  it  dyes  wool  bluish-black  in  acid  bath. 

Typical  Reaction. — It  appears  in  the  form  of  a  bluish-black 
powder  dissolving  to  a  dark  blue-violet  solution  in  water.  The 
watery  solution  becomes  a  blue-violet  by  the  action  of  hydro- 
chloric acid,  acetic  acid,  sodium  hydroxide,  and  ammonium 
hydroxide.  Ammoniacal  copper  solution  produces  a  fuchsin-red 
liquid  but  no  precipitate.  Barium  chloride  and  ferric  chloride 
produce  bluish-violet  precipitates  difficultly  soluble  in  water. 
The  powder  dissolves  in  concentrated  sulphuric  acid  to  a  dirty- 
green  solution,  which  becomes  blue  on  dilution  with  water. 

Exp.  I. — Dog  weighing  26730  grams,  the  urine  of  which  contained 
little  albumin,  received,  March  3d,  3  grams  by  the  tube.  Urine 
remained  almost  uncolored,  and  showed  but  little  albumin.  No 
appreciable  change  was  produced  by  either  hydrochloric  acid  or 
sodium  hydroxide.  March  4th  to  5th,  3  grams  by  the  tube.  Albumin 
distinct,  urine  uncolored.  Faeces  colored  blue.  March  5th  to  6th,  5 
grams,  urine  colored  a  weak,  reddish-violet,  becomes  fuchsin-red  with 
hydrochloric  acid.  March  6th  to  8th,  albumin  slight ;  animal  lively, 
took  food  freely,  March  9th  to  loth,  urine  dirty,,  bluish-red,  colored 
orange-red  with  hydrochloric  acid  ;  bluish-red  with  sodium  hydroxide  ; 
the  acidified  liquid  dyes  wool.  March  12th,  10  grams  administered. 
Animal  took  food;  urine  blue.  March  13th,  urine  as  before,  litde 
albumin.     March  14th,  20  grams  administered.     Rather  much  albu- 


SECONDARY    DISAZO-COLORS.  1 39 

min  ;  animal  lively;  took  food.  "March  15th,  urine  bluish,  albumin 
distinct.  March  19th,  urine  colorless,  albumin  slight.  March  21st, 
weight,  26,620  grams, 

A  second  dog  weighing  4500  grams  received  during  one  month, 
daily,  one  gram  of  the  color.  It  remained  entirely  well  with  good 
appetite. 

Exp.  J. — Dog  weighing  3200  grams,  of  which  the  urine  was  color- 
less and  free  from  albumin,  received,  March  5th,  o.i  gram  subcuta- 
neously,  dissolved  in  10  c.c.  of  lukewarm  water,  introduced  under  the 
skin  of  the  back  on  the  right  side.  March  6th,  urine  scanty,  uncolored, 
no  albumin  ;  no  abscess.  March  7th,  o.i  gram  subcutaneously.  Animal 
took  but  little  food.  March  8th,  no  abscess  ;  urine  uncolored,  no 
albumin,  took  no  food.  March  9th,  died  during  the  preceding  night. 
Weight,  2250  grams.  Post-mortem  showed  no  abscess,  no  induration 
at  the  point  of  injection ;  much  unchanged  color  under  the  skin  at 
the  point  of  injection,  which  was  free  from  microorganisms.  Gelatin 
plates  inoculated  with  the  color  taken  from  the  point  of  injection 
remained  sterile  during  nine  days.  The  body  was  not  yet  rigid,  but 
much  emaciated.  The  mucous  membranes  were  of  normal  color  ;  the 
intestines  were  pale;  mesenteric  vessels  were  much  injected.  The 
liver,  pancreas,  kidneys,  and  lungs  were  strongly  hyperasmic  ;  no 
exudates  were  noted. 

Exp.  4. — Dog  weighing  3860  grams,  which  had  been  used  for 
another  experiment  and  very  much  emaciated,  the  urine  being  un- 
colored and  containing  a  little  albumin,  received,  March  12th,  0.1  gram 
subcutaneously  in  10  c.  c.  of  water.  March  13th,  no  abscess;  animal 
miserable ;  urine  scanty,  almost  uncolored,  no  color  change  with 
sodium  hydroxide,  acetic  acid,  or  hydrochloric  acid  ;  albumin  dis- 
tinct; .1  gram  of  the  color  subcutaneously.  March  14th,  0.1  gram 
subcutaneously.  Urine  colorless  ;  no  abscess.  March  i6th,  urine 
colorless ;  albumin  very  distinct ;  animal  took  food  but  was  very 
miserable.  March  19th,  no  abscess  ;  animal  very  much  emaciated  ; 
albumin  distinct.  March  21st,  took  food  abundantly.  Weight,  3887 
grams.  March  25th,  animal  very  thin  ;  took  food,  and  was  killed 
by  hydrogen  cyanide.  Post-mortem.  The  subcutaneous  cellular 
tissue  beneath  the  point  at  which  the  injections  were  made  was  deep 
bluish-red,  and  the  muscles  showed  the  same  color.  The  liver  and 
other  glands  were  strongly  hypersemic  and  hypertrophied,  and 
the  intestines  were  slightly  bluish-red.  The  conjunctiva  and  mucous 
membrane  of  mouth  were  not  colored. 


140 


THE    COAL-TAR   COLORS. 


This  color  is  harmless  when  administered  by  the  stomach,  but 
poisonous  subcutaneously. 

DISAZO-COLORS  OF  THE  CONGO  GROUP. 
Congo  Red. 

This  color  is  obtained  by  diazotizing  benzidine,  and  uniting 
the  tetrazo-compound  with  two  molecules  of  a-amidonaph- 
thalenesulphonic  acid.  Its  constitutional  formula  is,  therefore, 
as  follows  :  — 


N     =      N 


NH2  NaSOg 


N 


NH2  NaSOg 


The  commercial  article  is  sodium  benzidinedisazo-a-amidonaph- 
thalenesulphonate-a-amidonaphthalenesulphonate.  My  specimen 
was  obtained  from  the  Aniline  Manufacturing  Company  of 
Berlin. 

Typical  Reaction. — It  is  a  red  powder,  producing  with  water 
a  blue  solution  in  which  hydrochloric  and  acetic  acids  pro- 
duce blue  precipitates  scarcely  soluble  in  hot  water.  Sodium 
hydroxide  produces  in  concentrated  solution  a  reddish-brown 
color  but  slightly  soluble  in  water.  Ammoniacal  copper  solution 
produces  a  gelatinous  red  precipitate,  soluble  in  excess  of  water 
with  a  red  color.  The  powder  dissolves  in  concentrated  sul- 
phuric acid  to  a  blue  solution,  which  on  dilution  with  water 
gives  a  blue  precipitate.  It  colors  cotton  and  wool  without  a 
mordant. 

Exp.  J. — Dog  weighing  7300  grams,  showing  very  slight  albumin- 
uria, received,  December  i8th,  two  grams  of  the  Congo  red  dissolved 


DISAZO  COLORS    OF   THE    CONGO    GROUP.  I41 

in  peptone  administered  by  the  tube.  Animal  lively  ;  urine  entirely 
normal  in  color.  December  19th,  two  grams  of  the  color  administered. 
Urine  pale,  feebly  alkaline,  traces  of  albumin,  no  sugar.  December 
20th,  two  grams  of  the  color  administered.  Urine  a  weak  red  color, 
no  change  on  addition  of  acids,  becomes  yellow  with  sodium  hydrox- 
ide;  little  albumin.  December  21st,  three  grams  of  the  color.  Ani- 
mal lively  ;  urine  somewhat  reddish  ;  cotton  could  not  be  colored  with 
the  urine  without  previous  preparation,  and  the  dyed  stuff  turned  red 
on  treatment  with  acids  ;  little  albumin.  December  23d  to  26th,  ani- 
mal lively  ;  urine  weak  reddish  in  color  and  gives  a  reddish  sediment, 
probably  Congo  red.  December  27th,  five  grams  in  peptone.  Ani- 
mal lively  ;  urine  almost  uncolored,  feebly  alkaline;  some  albumin. 
December  28th,  ten  grams  of  Congo  red  ;  but  little  albumin  in  the 
urine  ;  cotton  dyed  easily.  December  30th,  ten  grams.  Animal  took 
but  little  food,  but  was  otherwise  comfortable  ;  urine  but  little  colored, 
feebly  alkaline,  little  albumin,  sulphates  present ;  weight,  6980  grams; 
lost,  therefore,  320  grams  in  sixteen  days.  December  31st,  animal 
lively;  experiment  discontinued.  January  15th,  animal  in  good  con- 
dition. 

A  second  dog  weighing  4300  grams  received  during  one  month 
daily  one  gram  of  Congo  red  with  the  tube.  It  remained  entirely 
well. 

Exp.  3. — Dog  weighing  4970  grams,  showing  traces  of  albumin  in 
urine,  received,  January  5th,  1889..  .25  gram  of  Congo  red  dissolved  in 
10  c.c.  of  water  introduced  under  the  skin  on  the  right  side  of  the 
back.  January  6th,  urine  scarcely  colored,  almost  free  from  albumin. 
January  7th,  .25  gram  injected  similarly;  urine  uncolored,  alkaline, 
but  little  albumin  ;  animal  seemed  weak.  January  8th,  took  but  little 
food ;  urine  uncolored ;  no  abscess.  January  9th,  urine  uncolored, 
and  but  little  food  taken  ;  .25  gram  introduced  under  the  skin  of  the 
back  on  the  left  side.  Abscess  appeared  on  the  abdomen  to  the  right 
of  the  mesial  line.  January  loth,  but  little  food  taken  ;  urine  un- 
colored ;  .25  gram  administered  subcutaneously  under  the  skin  of 
the  left  side  of  the  back.  Large  abscess  to  the  left  of  the  linea  alba, 
January  nth,  animal  very  weak.  Urine  almost  uncolored  and  con- 
tained little  albumin.  A  large  abscess  on  the  right  side  of  the  abdo- 
men was  opened  and  about  15  c.c.  of  a  blood-red  liquid  was  dis- 
charged in  which  fatty  globules  could  be  seen  by  the  naked  eye.  The 
liquid  coagulated  in  about  ten  minutes,  and  after  suitable  dilution 
showed  the  oxyhasmoglobin  bands,  though  very  weakly.     Acids  made 


142  THE    COAL-TAR   COLORS. 

the  liquids  intensely  blue,  and  it,  therefore,  consisted  in  large  part  of 
unchanged  non-absorbed  color.  Microscope  showed  fatty  globules, 
red  blood  corpuscles,  some  of  which  were  normally  formed  and  some 
shriveled.  Pus  cells  were  also  present,  but  microbes  colored  by 
Gramm's  method  were  not  found.  January  12th,  animal  very  weak 
and  melancholy.  Weight,  4300  grams,  therefore  lost  670  grams  in 
eight  days.  January  13th  to  14th,  the  abscess  which  opened  on  Janu- 
ary nth  spontaneously  discharged  a  red  liquid  which  contained  much 
Congo  red,  as  was  indicated  by  the  bluing  by  acids.  The  opened 
abscess  on  the  left  side  seemed  to  have  been  absorbed.  Rectal  tem- 
perature 39.5°;  .25  gram  administered.  January  i6th,  animal  very 
miserable,  did  not  eat ;  rectal  temperature  39-5°;  the  opened  abscess 
seemed  about  to  close.  January  i8th,  rectal  temperature  39.2°;  ani- 
mal was  uncomfortable,  ate  but  little.  January  22d,  took  some  food  ; 
cross  and  miserable  ;  rectal  temperature  40.5°.  January  24th,  weak 
and  cross  ;  took  food.  January  29th,  one  abscess  opened  spontane- 
ously and  discharged  unchanged  color  mingled  with  some  pus. 
Animal  took  food  but  was  very  weak.  February  5th,  animal  again 
lively,  took  food.  The  abscess  over  the  abdomen  was  doubtless  a 
hypostatic  abscess  from  the  material  introduced  at  the  point  of  injec- 
tion. 

According  to  experiments  i  and  2,  Congo  red  is,  after  long- 
continued  administration  by  the  stomach,  harmless.  The  dis- 
turbances which  ensued  on  subcutaneous  injection  were  prob- 
ably dependent  upon  an  invasion  of  putrefactive  bacilli  and  had 
no  direct  relation  to  the  color. 


DISAZO-COLORS    OF    THE    CONGO    GROUP. 


143 


Azo-blue. 

This  coJor  is  produced  by  diazotizing  one  molecule  of  ortho- 
toluidine  and  joining  the  tetrazo-compound  so  formed  to  two 
molecules  of  a-naphtholmonosulphonic  acid  (N.  W.).  The  con- 
stitutional formula  is  as  follows:  — 


N        = 


CH, 


CH. 


N         =         N 


HO         NaSO, 


HO 


NaSO. 


and  the  color  is,  therefore,  sodium  tolidinedisazo-a-naphthol- 
monosulphonate  (N.  W.)  a-naphtholmonosulphonate  (N.  W.). 
The  specimen  used  was  obtained  from  the  Aniline  Manufacturing 
Company  of  Berlin.  The  color  dyes  cotton,  in  alkaline  bath, 
grayish  violet. 

Typical  Reactions. — It  is  a  bluish-black  powder  tolerably  easily 
soluble  in  water  to  a  red-violet  liquid.  The  watery  solution 
produces  with  hydrochloric  acid  a  reddish-violet  precipitate 
easily  soluble  in  water  and  alcohol.  Sodium  hydroxide  produces 
a  cherry-red  liquid.  Concentrated  sulphuric  acid  produces  in 
the  solution  a  blue  precipitate  that  is  soluble  in  excess  of  acid  to 
an  indigo-blue  liquid.  The  powder  dissolves  in  concentrated 
sulphuric  acid  to  an  indigo -blue  liquid  which  becomes  turbid  on 
the  addition  of  water  from  the  separation  of  a  violet  precipitate. 
The  precipitate  is  soluble  in  water  to  a  violet  solution.  The 
solution  of  the  color  in  concentrated  sulphuric  acid  is  decom- 
posed by  boiling,  becoming  brown.  Ammoniacal  copper  solu- 
tion produces  a  cherry-red  precipitate  that  is  difficultly  soluble 
in  water. 


144  THE    COAL-TAR   COLORS. 

Exp.  I. — Dog  weighing  8450  grams,  urine  of  which  was  pale  and 
contained  but  little  albumin,  received,  January  8th,  two  grams  dis- 
solved in  peptone  administered  by  the  tube.  January  29th,  animal 
was  lively,  took  food  ;  urine  was  uncolored.  Sodium  hydroxide  pro- 
duced a  transient  green  color;  albumin  doubtful.  January  loth,  two 
grams  by  the  tube.  Urine  uncolored,  but  had  a  violet  sheen ; 
strongly  alkaline  ;  little  albumin.  Sodium  hydroxide  and  ammonium 
hydroxide  produced  a  transient  greenish  tint.  No  characteristic  re- 
action with  ferric  chloride.  January  nth,  five  grams  by  the  tube; 
urine  colorless  ;  little  albumin.  Boiling  with  concentrated  sulphuric 
acid,  but  not  with  dilute  acetic  acid,  produces  a  distinct  bluish  black 
and  dark  color.  It  yields  to  ether  a  bluish  red  substance.  The  dis- 
tillate was  free  from  phenol.  January  12th,  eight  grams  adminis- 
tered.    Urine  abundant,  somewhat  bluish  violet.     Animal  lively. 

Urine  contained  but  little  albumin,  and  did  not  produce  alkahne 
copper  solution.  January  13th  to  14th,  no  administration.  Urine 
colorless.  January  15th,  urine  colorless.  Five  grams  of  the  color. 
January  i6th,  urine  colorless,  little  albumin.  January  i8th,  urine 
colorless,  little  albumin.  Five  grams  administered.  January  20th, 
urine  colorless,  little  albumin.     Weight,  8490  grams. 

Exp.  2. — Another  dog  weighing  4700  grams  received  during  one 
month  one  and  a  half  grams  daily  by  means  of  the  tube.  Animal 
remained  well,  with  good  appetite.  A  slight  amount  of  albumin 
made  its  appearance  in  the  urine. 

Exp.  3. — Dog  weighing  4600  grams,  showing  normal  urine,  re- 
ceived, January  29th,  .20  gram  in  10  c.  c.  of  water  subcutaneously  on 
the  left  side  of  the  back.  January  30th,  abscess  appeared  at  the  left 
side  ;  .20  gram  given  in  10  c.  c.  of  water  subcutaneously  on  the  right 
side  of  the  back.  January  31st,  abscess  on  the  left  side  opened,  and 
discharged  a  violet  gelatinous  mass  with  only  a  small  amount  of 
blood.  The  color  was  the  unchanged  azo-blue.  The  pus  contained 
numerous  pus  corpuscles  and  large  quantities  of  putrefactive  bacilli. 
The  urine  was  unchanged  in  color  and  contained  a  little  albumin. 
Weight,  4580  grams.  February  3d,  dog  ate  and  was  more  lively. 
February  7th,  .20  gram  under  the  skin  of  the  abdomen  with  a  care- 
fully sterilized  syringe  after  thorough  disinfection  of  the  parts  in- 
jected. February  loth,  no  abscess;  animal  lively.  February  15th, 
no  abscess.     February  24th,  ammal  lively,  no  abscess. 

Azo-blue  is  harmless,  both  when  administered  by  the  stomach 
and  subcutaneously.     Disturbances  produced  by  the  subcutan- 


DISAZO-COLORS    OF   THE    CONGO    GROUP. 


145 


eous  method  were  ascribable  to  the  introduction  of  putrefactive 

bacilli. 

Chrysamin  R. 

This  color  is  produced  by  diazotizing  one  molecule  of  o-toli- 
dine  in  conjugation  with  two  molecules  of  salicylic  acid.  The 
constitutional  formula  is  as  follows  : — 


HO 


N     -=     N 


CH. 


NaCO. 


CH. 


N 


N 


NaCO. 


HO 


The  color  is,  therefore,  sodium  orthotolidinedisazosalicylate- 
salicylate.  The  sample  was  obtained  from  the  Aniline  Man- 
ufacturing Company  of  Berlin. 

Typical  Reactions. — It  was  a  brownish  yellow  powder,  and 
produced  a  brown  solution  in  water.  This  solution  gave  with 
hydrochloric  acid  a  gelatinous,  brown  precipitate  which  was 
difficultly  soluble  in  water,  more  easily  in  alcohol,  to  a  brown 
color.  Acetic  acid  gives  a  brown  flocculent  precipitate.  Sodium 
hydroxide  gives  a  gelatinous,  reddish  brown  precipitate  soluble 
in  water  to  a  red-brown  color.  Ammonium  hydroxide  gives  a 
red-brown  solution.  Ammoniacal  copper  solution  gives  a  gela- 
tinous, red-brown  precipitate  difficultly  soluble  in  water.  The 
powder  dissolves  in  concentrated  sulphuric  acid  to  a  red-violet 
liquid  which  on  dilution  with  water  deposits  a  brownish  flocculi. 
Colors  cotton,  in  alkaline  bath,  yellow. 

Exp.  7. — Dog  weighing  9230  grams,  showing  normally  colored 
urine,  alkaline,  very  little  albumin,  and  plenty  of  sulphates,  received, 
on  January  3d,  five  grams  of  chrysamin  in  peptone  by  the  tube.  Urine 
was  alkaline  yellowish,  dyeing  of  cotton  easily  performed;  very  little 


146  THE    COAL-TAR   COLORS. 

albumin.  January  4th,  five  grams  of  the  color  administered.  Jan- 
uary 5th,  urine  yellowish,  became  red  by  sodium  hydroxide  ;  diar- 
rhoea ;  animal  took  food.  January  6th  to  7th,  animal  lively ;  slight 
diarrhoea ;  urine  almost  uncolored,  albumin  slight,  sulphates  abund- 
ant, alkaline.  January  7th,  one  gram  of  the  color.  Urine  slightly 
colored,  contained  distinct  amount  of  albumin.  January  8th,  urine 
slightly  colored,  some  albumin.  January  9th,  one  gram  administered. 
Animal  lively.  January  loth,  two  grams  administered.  Animal 
lively;  wandered  about  freely  the  whole  day.  January  nth,  two 
grams  administered.  Animal  lively.  January  12th,  three  grams  of 
the  color.  January  13th,  animal  lively,  took  food.  January  14th, 
weight,  9600  grams;  therefore,  a  gain  of  370  grams  in  12  days. 
January  15th,  lively.  Three  grams  of  the  color  administered.  Jan- 
uary 1 6th  to  20th,  albumin  slight,  animal  lively,  took  food. 

In  a  second  experiment,  an  animal  weighing  11,300  grams  took  in 
the  course  of  10  days  three  doses  of  seven  grams  each  of  the  color  by 
means  of  the  tube.  Urine  was  yellowish  in  color,  and  contained 
very  little  albumin.  Animal  remained  lively  even  14  days  after  the 
administration. 

Exp,  J. — A  dog  weighing  3680  grams,  urine  of  which  ^as  un- 
colored and  contained  traces  of  albumin,  received,  January  loth,  .25 
gram  of  the  color  in  10  c.  c.  of  lukewarm  water  subcutaneously. 
Urine  was  neutral,  somewhat  yellowish,  albumin  slight.  January 
nth,  animal  took  no  food;  no  abscess;  dyeing  of  cotton  did  not  suc- 
ceed ;  .25  gram  injected.  January  12th,  animal  weak,  no  abscess; 
urine  very  slightly  colored ;  albumin  slight;  .25  gram  was  injected. 
January  13th,  albumin  slight.  January  14th,  animal  melancholy; 
no  injection  ;  two  abscesses  on  the  back ;  40°  rectal  temperature. 
January  15th,  .25  gram  subcutaneously.  Urine  weakly  yellow;  al- 
bumin distinct;  does  not  color  cotton.  January  i6th,  no  injection, 
animal  cross  ;  temperature  39.5°  ;  took  little  food.  One  of  the  abscess- 
es of  the  back  opened  spontaneously  and  discharged  a  yellow  liquid 
(chrysamin).  January  17th,  animal  cross  ;  rectal  temperature  39.5°; 
abscess  as  above.  January  i8th,  abscess  discharged  but  little  color. 
January  19th  to  21st,  temperature  39.5°;  cross;  had  taken  little  food. 
There  seemed  to  be  a  new  abscess  forming,  January  22d,  ate  but 
little. 

The  abscesses,  which  were  opened  with  a  knife,  discharged  about 
20  c,  c.  of  a  gelatinous  mass  exhibiting  the  color  of  injected  dye,  and 
in  which  the  unchanged  material  itself  was  found.     Bacteria  were 


CONCLUSIONS.  147 

not  with  perfect  certainty  recognizable  in  the  discharged  hquid,  and 
those  which  are  colored  by  Gramm's  method  were  completely  absent. 
Many  fatty  globules,  only  traces  of  albumin.     Weight,  3210  grams. 

Chryiramin  is  harmless  when  taken  into  the  stomach.  The 
abscess  produced  by  subcutaneous  administration  may  be 
referable  to  putrefactive  organisms,  although  these  were  not 
definitely  recognized. 

CONCLUSIONS. 

Of  the  23  azo-colors  subjected  to  examination  only  two, 
metanil  yellow  and  orange  II,  produce  such  effects  when  admin- 
istered by  the  stomach  that  we  can  consider  them  poisonous. 
With  dogs,  the  lethal  dose  is  less  than  one  gram  per  kilo  of  the 
body  weight  of  orange  II,  and  only  .53  gram  per  kilo  of  metanil 
yellow.  Of  the  remaining  colors  some  produce  vomiting  {e.g., 
Bismarck  brown),  and  others  diarrhoea  (fast  brown,  chrysamin 
R),-and  many  develop  a  slight  albuminuria.  The  phenomena 
produced  by  subcutaneous  administration  are  not  all  susceptible 
of  the  same  interpretation.  The  abscesses  were  in  some  cases 
(for  instance,  azo-blue)  referable  to  the  invasion  of  microor- 
ganisms. Naphthol  black  P.,  however,  is  plainly  poisonous 
when  introduced  into  the  subcutaneous  cellular  tissue.  A  strik- 
ing fact  is  how  long,  in  some  cases,  the  aqueous  solution  of  the 
color  remains  unabsorbed  in  the  subcutaneous  cellular  tissue. 
Congo  red,  for  instance,  in  Experiment  3  could  be  recog- 
nized in  considerable  amount  seven  days  after  the  injection. 
Similar  observations  were  made  with  chrysamin. 

The  investigations  of  the  color  prepared  from  the  w-ni- 
traniline  and  /5-napbthol,  /-nitraniline  and  Schgeffer's  salt,  /- 
nitraniliue  and  naphthionic  acid  (archil-substitute),  showed  that 
the  introduction  of  a  nitro-group  into  an  azo-color  does  not 
necessarily  produce  a  poisonous  body,  this  being  contrary  to 
what  the  experiments  with  the  nitro-colors  proper  has  led  us  to 
anticipate.  This  harmlessness  of  the  nitro-group  in  the  azo- 
colors  is  not,  however,  due  to  the  presence  of  the  sulphonic  acid 
group, — the  detoxicating  influence  of  which  was  recognized  in 
connection  with  the  nitro-group.  For  instance,  w-nitrazotin, 
prepared  from  w-nitraniline   and  /5-naphthol,  contains  no  sul- 


148  THE   COAL-TAR   COLORS. 

phonic  group  and  yet  is  non-poisonous,  in  spite  of  the  nitro- 
group  present.  Further,  in  spite  of  the  presence  of  the  sulphonic 
groups,  colors  may  be  poisonous,  as  is  shown  with  orange  II,  pre- 
pared from  /-amidobenzenesulphonic  acid  and  /3-naphtho],  and 
metanil  yellow,  prepared  from  ///-amidobenzenesulphonic  acid 
and  diphenylamine.  The  poisonous  qualities  of  orange  II  and 
metanil  yellow  are  not  referable  with  certainty  to  their  consti- 
tution, since  two  other  colors  of  known  constitution,  closely 
analogous  to  them  have  been  shown  to  be  non-poisonous.  For 
instance,  the  poisonous  metanil  yellow  corresponds  to  the  non- 
poisonous  diphenylamine  orange.  The  difference  between  the 
two  is  in  the  relation  between  the  sulphonic  group  and  the 
azo-group.  In  diphenylamine  orange,  these  groups  stand  to  each 
other  in  the  para-position  ;  in  metanil  yellow,  in  the  meta-posi- 
tion.  The  correctness  of  these  formulae  is  shown  by  the  fact 
that  the  metanil  yellow  is  obtained  by  the  diazotizing  of  w-ami- 
dobenzenesulphonicacid,  while  diphenylamine  orange  is  obtained 
by  diazotizing /-amidobenzenesulphonic  acid.  Further,*  orange 
II,  which  is  poisonous,  corresponds  to  another  color,  orange  I, 
which  is  not  poisonous.  These  bodies  differ  only  in  the  position 
of  the  hydroxyl  in  the  naphthalene  residue.  In  orange  II  the 
hydroxy!  has  the  /5-position  ;  in  orange  I,  the  a-position.  This 
is  shown  by  the  methods  of  preparing  the  colors,  one  being 
made  from  «-  and  the  other  from  /J-naphthol.  Other  azo- 
colors  which  contain  the  /5-naphthol  residue,  for  instance, 
Soudan  I,  new  coccin,  fast  red  B,  xylidine  red,  and  azarin  S, 
are  entirely  non-poisonous. 

The  urine  obtained  from  the  animals  fed  or  treated  subcutane- 
ously  with  the  azo-colors  was  generally  colored  and  contained  the 
unchanged  color  only  when  considerable  quantities  of  the  mate- 
rial had  been  administered.  A  portion  of  the  color  adminis- 
tered was  found  in  the  faeces,  and  especially  when  the  color  was 
insoluble.  Generally  the  complex  color  molecule  is  split  up  in 
the  animal  organism  into  uncolored  derivatives.  When  animals 
to  which  azo-colors  have  been  administered  have  excreted  a 
urine  of  normal  color,  I  have  never  been  able  to  obtain  any 
coloring  materials  analogous  to  the  azo-body  used. 


APPENDIX. 


Formation  of  Dyestuffs. — The  conditions  under  which 
an  uncolored  body,  or  one  not  capable  of  coloring  fibres,  be- 
comes converted  into  a  dyestuff  are  explained  by  the  following 
theoretical  suggestions  of  O.  N.  Witt. 

Witt  assumes  the  presence  of  certain  characteristic  groups — 
chromophorous  groups — in  all  dyestuffs,  which,  by  introduction 
into  colorless  bodies,  give  rise  to  the  basis  structure  of  dyestuffs — 
chromogenous  groups.  When  these  chromogenous  groups  are 
joined  to  salt-forming  groups,  such  as  hydroxyl  or  amidogen, 
dyestuffs  are  formed. 

The  following  are  examples  of  chromophorous  groups  : — 


-NO, 

characteristic  for  nitro- colors. 

—  NO 

"              "   nitroso-colors. 

—  N^:.:  N- 

—        "               "    azo-colors. 

R  —  N 

1 
C    ~J 

"              "    rosaniline  colors, 

R  — O 

I  I 

C > 

il 

R  —  CO 

i-ci 

CO 

1 1 

CO 


"  "    rosolic  acid  colors. 

"  "   phthalein  colors  (eosin,  etc.). 

"  "   anthraquinone  colors  (alizarin), 

149 


150  THE    COAL-TAR   COLORS 

I 
R  — N 

N — — I    characteristic  for  indamines. 


"    indophenols. 


R- 

1 

-0 

1 

N 

1 

R- 

1 

-  s 

1 

1 

N- 

1 

-  R 

1 

N 

J 

"    methyl  blue,  etc. 


N  =  N  (azine  group)  characteristic  for  azines,  safranine,  etc. 

—  CO  —  C  = 

I  .  "  "    indigo. 

—  NH 

Azobenzene,  CgHj  —  N  =  N  —  CgHg,  contains  the  chromo- 
phorous  group  —  N  =  N  — ,  and  is  a  chromogen,  but  not  a  dye, 
because  it  has  no  affinity  for  fibres.  By  introduction  of  NH^,  or 
HO,  we  obtain  respectively  amidoazobenzene  and  hydroxyazo- 
benzene,  both  of  which  are  dyes.  Salt-forming  groups,  which  de- 
velop the  coloring  power  of  bodies,  are  called  ''auxochromous" 
groups. 

Representing  by  R,  Rx,  Ry,  Rz  various  hydrocarbon  radicles, 
we  may  express  the  principal  types  of  azo-compounds  as  fol- 
lows :  — 

Monazo-colors :  — 


R- 

-  N  = 

=  N  —  Rx  HO 

R- 

-N:. 

x^       p     HO 

-  j\  —  Ry 

HSO3 

R- 

-  N.- 

-  N  —  Rx  NH, 

R- 

-Nzz 

.N-RxOH 
HSO, 

APPENDIX. 


151 


Primary  diazo-colors  :• 


R    _N-^N\p 
R    _  N  :=  N  / 


R    _  N  =  N 
Ry  —  N 


zS}*^^ 


no 


HO 


Ry::N=:S^R'<NH, 


"} 


R    ._  N  =  N 
Rx—  N 


-^JRyNH, 


Fast  brown,  for  instance,  is — 


NaSO 


NaSO. 


Secondary  diazo-colors :  — 

Note  to  page  100. — It  is  to  be  noted  that  diazo-compounds  are 
produced  when  nitrous  acid  acts  on  the  salts  of  primary  amines 
of  the  benzene  series  at  low  temperatures: — 


CgH-  —  NH^HCl  +  HNO3 

Aniline  hydrochloride. 


^6^5 


_  N  =  N  —  CI  +  2H,p 

Diazobenzene  chloride. 


If  primary  diamines  are  employed  under  the  same  conditions, 
tetrazo-compounds  are  formed:  — 

CgH^  —  NH.,HCI  CgH^  _  N  =  N  —  CI 

I  ^         +  2HNO3  =   I  +  4H.,0 

CgH^  —  NH.HCl  CgH^  —  N  =  N  —  CI 

Diamidodiphenyl  hydrochlor'de.  Tetrazodiphenyl  chloride. 

The  nitrous  acid  can  be  applied  in  the  condition  of  vapor 
(obtained  by  the  action  of  nitric  acid  upon  arsenious  oxide  or 
starch),  led  into  the  cooled  mixture  of  the  amine  and  water, 
until  saturation  is  reached  and  the  diazo-compound  separated  by 
the  addition  of  alcohol  and  ether.  It  is  usual,  however,  to  em- 
ploy solutions  of  sodium  or  potassium  nitrite  of  known  strength, 
which  are  added  to  the  well-cooled  solution  of  the  amine  salt. 
Sufficient  hydrochloric  acid  must  be  present  to  liberate  the 
equivalent  amount  of  nitrous  acid. 


INDEX. 


Acid  yellow  S,  89,  128 
Administration  methods,  56 
Alsace  green,  62 
Aniline  blue,  22,  24 

brown,  116 

orange,  71 

red,  22 

violet,  24 

yellow,  89,  128 
Archil-substitute,  1 24 
Arsenic,  detection  of,  39,  43 
Arsenical  fuchsin,  22 

mordants,  26 
Aurantia,  31,  94 
Austro-Hungary,  laws  of,  48 
Auxochromous,  150 
Azarin  S,  132 
Azo-blue,  143 

colors,  96 

compounds,  97 

rubin  S,  115 

Bismarck  brown,  116 
Brilliant  orange,  123 

yellow,  92 
Butter  yellow,  31 

Cardinal,  31 

Chromogens,  150 

Chromophores,  150 

Chrysamin  R,  145 

Chrysoidin,  126 

Citronine,  89 

Classification  of  colors,  17,  113 

Conclusion,  147 

Congo  red,  140 

Corallin,  24 

Coupage,  19 

Crocein,  123 

Dahlia,  24 
13 


Detection  of  colors,  22,  26 

of  metals,  39 
Diazo-compounds,  98 
Diisonitrosoresorcinol,  61 
Dinitrocresol,  71 
Dinitroresorcinol,  61 
Diphenylamine,  128 
Disazo-colors,  134 

English  brown,  1 16 

law,  45 
Enlevage,  21 
Eosin,  26,  31 
Erythrosin,  31 

Fast  brown  G,  134 

Fastness,  21 

Fast  yellow,  89 

Formation  of  dye-stuffs,  149 

French  law,  46 

Fuchsin,  22 

German  laws,  35,  45 
Golden  yellow,  71 

Health  of  operatives,  30 

Imperial  yellow,  94 
Italian  law,  47 

Laws  relating  to  colors,  31,  35 
Light  blue,  23 
Lyon's  blue,  23 

Malachite  green,  24 
Manchester  brown,  116 

yellow,  85 
Mandarin,  121 
Martins'  yellow,  85 
Metanil  yellow,  130 
Metanitrazotin,  119 


153 


154 


INDEX. 


Methylene  blue,  31 

Naphthalene  yellow,  85 
Naphthol  black  P,  138 

green  B,  63 

yellow,  85 

yellow  S,  89 
New  yellow,  89,  128 
Nitro-colors,  destruction  of,  66 

group,  influence  of,  92,  115 
Nomenclature,  18,  113 

Orange,  31 
B,  128 
G  S,  128 

1,115 
II,  121 
IV,  128 

MN,  130 

Paranitrazotin,  120 

Picric  acid,  68 
Poisonous  colors,  22 
Ponceau  R,  31 
4  GB,  123 


Purple,  31 

Reservage,  21 

Resorcinol  green,  62 
Rosolic  acid,  26 

Saffron-substitute,  71 

yellow,  85,  89 
Safranin,  31 
Solid  green,  62 

yellow,  31,  89 
Soudan  I,  118 
Sulphonic  acids,  loi 

group,  influence  of,  92 

Tin,  detection  of,  42 
Tropseolin  00,  128 
000,  115,  121 

Vesuvin,  116 
Victoria  orange,  71 
yellow,  71 

Witt's  theory  of  colors,  149 
Wool  black,  136 


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SUBJECT  INDEX. 


Gould's  Medical  Dictionaries,  -  Pages  12,  13 
Morris*  Anatomy,  New  Edition,  -  -  Page  4 
Compends  for  Students,  -      -      -      -       Page  27 


SUBJECT.  PAQB 

Alimentary  Canal  (see  Sur- 
gery)     24 

Anatomy    7 

Anesthetics    18,  19 

Autopsies  (see  Pathology)  20 

Bacteriology    8 

Bandaging  (see  Surgery)  . .   24 
Blood,  Examination  of . . .     8 

Brain 8 

Chemistry.     Physics    ....     9 

Children,  Diseases  of 11 

Climatology 19 

Clinical  Charts 25 

Compends 27 

Consumption  (see  Lungs) .    16 
Cyclopedia  of  Medicine ...    13 

Dentistry 11 

Diabetes(seeUrin.  Organs)  25 

Diagnosis 11 

Diagrams  (see  Anatomy) .      8 
Dictionaries,  Cyclopedias.    12 

Diet  and  Food 13 

Disinfection 16 

Dissectors 7 

Ear   14 

Electricity    14 

Embryology 7 

Emergencies 24 

Eye 14 

Fevers 15 

Food 13 

Formularies 21 

Gynecology    15 

Hay  Fever 25 

Heart    15 

Histology 15 

Hydrotherapy 19 

Hygiene    16 

Hypnotism 8 

Insanity 8 

Intestines 23 

Latin,  Medical  (see  Phar- 
macy)      21 

Life  Insurance 19 

Lungs 16 

Massage    17 

Materia  Medica 17 

Mechanotherapy 17 

Medical  Jurisprudence ....    18 


SUBJECT.  PAoa 

Mental  Therapeutics 8 

Microscopy 18 

Milk 8,10 

Miscellaneous 18 

Nervous  Diseases 19 

Nose    25 

Nursing 20 

Obstetrics 20 

Ophthalmology 14 

Organotherapy    18 

Osteology  (see  Anatomy)  .     7 

Pathology 20 

Pharmacy 21 

Physical  Diagnosis 11 

Physical  Training 17 

Physiology 22 

Pneumotherapy 19 

Poisons  (see  Toxicology)  . .    18 

Practice  of  Medicine 22 

Prescription  Books  (Phar- 
macy)     21 

Refraction  (see  Eye) 14 

Rest 19 

Sanitary  Science n   16 

Serum-Therapy 17 

Skin ♦. . .   23 

Spectacles  (see  Eye) .....    14 
Spine    (see    Nervous    Dis- 
eases)       19 

Stomach 23 

Students'   Compends .....   27 
Surgery  and  Surgical  Dis- 
eases      24 

Technological  Books .....     9 

Temperature  Charts 25 

Therapeutics   17 

Throat 25 

Toxicology 18 

Tumors  (see  Surgery) ....   24 

U.  S.  Pharmacopoeia 22 

Urinary  Organs 25 

Urine 25 

Venereal  Diseases 26 

Veterinary  Medicine 26 

Visiting  Lists,  Physicians'. 
(Send  lor  Special  Circu- 
lar.) 

Water  Analysis 16 

Women,  Diseases  of 15 


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some full-page  Illustrations  Engraved  from  Original  Drawings 
made  by  special  Artists  from  dissections  prepared  for  the  pur- 
pose.    Three  vols.     By  Subscription  only. 

Half  Morocco  or  Sheep,  $24.00 ;  Half  Russia,  $27.00 

GORDINIER.     Anatomy  of  the  Central  Nervous  System.    With 
271  Illustrations,  many  of  which  are  original.       Cloth,  $6.00 
HEATH.     Practical  Anatomy.    9th  Edition.    321  Illus.       $4.25 
HOLDEN.     Anatomy.    A  Manual  of  Dissections.    Revised  by  A. 
Hbwson,  M.D.,  Demonstrator  of  Anatomy,  Jefferson  Medical 
College,  Philadelphia.     320  handsome  Illustrations.     7th  Ed. 
In  two  compact  12mo  volumes.     850  pages.    Large  New  Type. 
Vol.  I.  Scalp— Face— Orbit— Neck— Throat— Thorax — Up- 
per Extremity.  $1.60 
Vol.  II.  Abdomen — Perineum — Lower  Extremity — Brain — 
Eve — Ear — Mammary  Gland — Scrotum — Testes. 

$1.50 

HOLDEN.  Human  Osteology.  Comprising  a  Description  of  the 
Bones,  with  Colored  Delineations  of  the  Attachments  of  the 
Muscles.  The  General  and  Microscopical  Structure  of  Bone 
and  its  Development.  With  Lithographic  Plates  and  numer- 
ous Illustrations.     8th  Edition.  $6.26 

HOLDEN.     Landmarks,  Medical  and  Surgical.    4th  Ed.  .75 

HUGHES  AND  KEITH.  Dissections.  With  527  Colored  Plates 
and  other  Illustrations.     In  three  parts. 

I,  Upper  and  Lower  Extremity.  $3.00 

II,  Abdomen— Thorax'.  $3.00 

III,  Head — Neck — Central  Nervoxis  System.  $3.00 

LAZARUS-BARLOW.     Pathological  Anatomy.     21  Plates  and 

171  other  Illustrations.     Just  Ready.  $6.60 

McMURRICH.     Embryology.    The  Development  of  the  Human 

Body.     276  lUustrations.  $3.00 


8  SUBJECT  CATALOGUK 

MARSHALL.  Physiological  Diagrams.  Eleven  Life-Size 
Colored  DiaKrama  (each  seven  feet  by  three  feet  seven  inches). 
Designed  for  Demonstration  before  the  Class. 

In  Sheets,  Unmounted,  $40.00;  Backed  with  Muslin  and 
Moxinted  on  Rollers,  $60.00;  Ditto,  Spring  Rollers,  in  hand- 
some Walnut  Wall  Map  Case,  $100.00;  Single  Plates— Sheets, 
$5.00;  Mounted,  $7.60.  Explanatory  Key,  .50.  Purchaser 
must  pay  freight  charges. 

MINOT.  Laboratory  Text-Book  of  Embryology.  218  Illustra- 
tions.    Just  Ready.  $4.50 

POTTBR.  Compend  of  Anatomy,  Including  Visceral  Anatomy. 
7th  Edition,  Revised  and  Enlarged.  16  Plates  and  138  other 
Illustrations.     Just  Beady.  .80;  Interleaved,  $1.00 

WILSON.     Anatomy.    11th  Edition.    429  Illus.,  26  Plates.    $5.00 

YUTZY.  Guide  to  the  Dissection  of  the  Human  Body.  Based 
on  Morris'  Anatomy.  Paper  Cover,  .25 

BACTERIOLOGY- 

CONN.  AgricTiltural  Bacteriology,  Including  the  Study  of 
Bacteria  as  relating  to  Agriculture,  Soil,  Dairy  and  Food 
Products,  Sewage,  Domestic  Animals,  etc.    Illustrated.    $2.50 

CONN.  Bacteria  in  Milk  and  Its  Products.  Designed  for 
Students  of  Dairying,  Boards  of  Health,  Bacteriologists,  etc. 
Illustrated.  $1.25 

EMERY.  Bacteriological  Diagnosis.  2  Colored  Plates  and  32 
other  Illustrations.  $1.50 

HEWLETT.  Manual  of  Bacteriology.  75  Illustrations.  Second 
Edition,  Revised  and  Enlarged.  $4.00 

SMITH.  Laboratory  Exercises  in  Bacteriology.  A  Handbook 
for  Students.     Illustrated.  $1.50 

WILLIAMS.  Bacteriology.  A  Manual  for  Students.  99  Illus- 
trations.    3d  Edition,  Revised.     Just  Beady.  $1.50 

BLOOD,  Examination  of. 

DA  COSTA.  Clinical  Hematology.  A  Practical  Guide  to  the 
Examination  of  the  Blood,  with  Reference  to  Diagnosis.  Six 
Colored  Plates  and  48  other  lUus.       Cloth.  $5.00 ;  Sheep,  $6.00 

BRAIN  AND  INSANITY  (see  also 
Nervous  Diseases.) 

BLACKBURN.     A  Manual  of  Autopsies.     Designed  for  the  Use 

of  Hospitals  for  the  Insane  and  other  Public  Institutions.    Ten 

full-page  Plates  and  other  Illustrations.  $1.25 

CHASE.     General  Paresis.     Illustrated.  $1.75 

DERCUM.     Mental  Therapeutics,  Rest,  Suggestion.    See  Cohen, 

Physiologic  Therapeutics,  page  17. 

60RDINIER.     The  Gross  and  Minute  Anatomy  of  the  Central 

Nervous  System.     With  full-page  and  other  lUus.         $6.00 

IRELAND.    The  Mental  Affections  of  Children.     2d  Ed.     $4.00 

LEWIS    (BEVAN).     Mental    Diseases.      A   Text-Book   having 

Special  Reference  to  the  Pathological  Aspects  of  Insanity.    26 

Lithographic  Plates  and  other  Illustrations.     2d  Ed.     $7.00 


MEDICAL  BOOKS.  9 


MAIVN.     Manual  of  Psychological  Medicine.  S3.00 
PERSHING.      Diagnosis  of  Rervout  and  Mental  Disease.  Illus- 
trated. $1-25 
REGIS.     Mental  Medicine.     Authorised  Translation  by  H.  M. 
Bankistsr,  u.d.  $2.00 

STEARNS.  Mental  Diseases.  With  a  Digest  of  Laws  Relating 
to  Care  of  Insane.    Illustrated.         Cloth,  $2.75;  Sheep,  $3.25 

TUEIE.  Dictionary  of  Psychological  Medicine.  Giving  the 
Definition,  Etymology,  and  Symptoms  of  the  Terms  used  in 
Medical  Psychology,  with  the  Symptoms,  Pathology,  and 
Treatment  of  the  Recognized  Forms  of  Mental  Disorders. 
Two  volumes.  $10.00 

WOOD,  H.  C.     Brain  and  Overwork.  .40 

CHEMISTRY  AND   TECHNOLOGY. 

Special  Catalogue  of  Chemical  Book*  $ent  free  upon  application. 

ALLEN.  Commercial  Organic  Analysis.  A  Treatise  on  the 
Modes  of  Assaying  the  Various  Organic  Chemicals  and  Prod- 
ucts Employed  in  the  Arts,  Manufactures,  Medicine,  etc., 
with  Concise  Methods  for  the  Detection  of  Impurities,  Adul- 
terations, etc.     8vo. 

Vol.  I.    Alcohols,  Neutral  Alcoholic  Derivatives,  etc..  Ethers, 
Vegetable  Acids,  Starch,  Sugars,  etc.     3d  Edition.     $4.50 
Vol.  II,  Part  I.     Fixed  Oils  and  Fats,  Glycerol,  Explosives, 
etc.     3d  Edition.  $3.50 

Vol.  II,  Part  11.  Hydrocarbons,  Mineral  Oils,  Lubricants, 
Benzenes,  Naphthalenes  and  Derivatives,  Creosote,  Phenols, 
etc.     3d  Edition.  $3.60 

Vol.  II,  Part  III.  Terpenes,  Essential  Oils,  Resins,  Camphors, 
etc.     3d  Edition.  In  Press. 

Vol.  Ill,  Part  I.  Tannins,  Dyes,  and  Coloring  Matters.  3d 
Edition,  Enlarged   and   Rewritten.     Illustrated.  $4.50 

Vol.  Ill,  Part  II.  The  Amines,  Hydrazines  and  Derivatives, 
Pyridine  Bases.  The  Antipyretics,  etc.  Vegetable  Alka- 
loids, Tea,  Coffee,  Cocoa,  etc.  8vo.  2d  Edition.  $4.50 
Vol.  Ill,  Part  III.  Vegetable  Alkaloids,  Non-Basic  Vegetable 
Bitter  Principles.  Animal  Bases,  Animal  Acids,  Cyanogen 
Compounds,  etc.     2d  Edition,  8vo.  $4.50 

Vol.  IV.  The  Proteids  and  Albuminous  Principles.  2d 
Edition.  ^  $4.50 

BAILEY  AND  CADY.     Qualitative  Chemical  Analysis.       $1.25 
BARTLEY.     Medical  and  Pharmaceutical  Chemistry.     A  Text- 
Book  for  Medical,  Dental,  and  Pharmaceutical  Students.   With 
Illustrations,  Glossary,  and  Complete  Index.    6th  Ed.    $3.00 

BARTLEY.  Clinical  Chemistry.  The  Examination  of  Feces, 
Saliva,  Gastric  Juice,  Milk,  and  Urine.  $1.00 

BLOXAM.  Chemistry,  Inorganic  and  Organic.  With  Experi- 
ments.    9th  Ed.,  Revised.     284  Engravings.  $6.00 

BUNGE.  Physiologic  and  Pathologic  Chemistry.  From  the 
Fourth  German  Enlarged  Edition.  $3.00 

CALDWELL.  Elements  of  Qualitative  and  Quantitative  Chem- 
ical Analysis.     3d  Edition,  Revised.  $1.00 


10  SUBJECT  CATALOGUE.' 


CAMERON.     Soap  and  Candles.     64  Illustrations.  $2.00 

CLOWES  AND  COLEMAN.  Quantitative  Analysis.  6th  Edi- 
tion.    125  Illustrations.  $3.50 

COBLENTZ.     Volumetric  Analysis.     Illustrated.  $1.25 

CONGDON.  Laboratory  Instructions  in  Chemistry.  With 
Numerous  Tables  and  56  Illustrations.  $1.00 

GARDNER.  The  Brewer,  Distiller,  and  Wine  Manufacturer. 
lUustrated.  $1.50 

GRAY.  Physics.  Volume  I.  Dynamics  and  Properties  of 
Matter.     350  Illustrations.  $4.50 

GROVES  AND  THORP.     Chemical  Technology.     The  Applica- 
tion of  Chemistry  to  the  Arts  and  Manufactures. 
Vol.  I.  Fuel  and  its  Applications.     607  Illustrations  and  4 
Plates.  Cloth,  $5.00;  i  Mor.,  $6.50 

Vol.  II.    Lighting.     Illustrated.       Cloth,  $4.00;  i  Mor.,  $5.50 
Vol.  III.  Gas  Lighting.  Cloth,  $3.50;  i  Mor.,  $4.50 

Vol.  IV.  Electric  Lighting.     Photometry. 

Cloth,  $3.50;  i  Mor.,  $4.50 

HEUSLER.     The  Chemistry  of  the  Terpenes.  $4.00 

HOLLAND.  The  Urine,  the  Gastric  Contents,  the  Common 
Poisons,  and  the  Milk.  Memoranda,  Chemical  and  Micro- 
scopical, for  Laboratory  Use.     6th  Ed.     Illustrated.       $1.00 

LEFFMANN.  Compend  of  Medical  Chemistry,  Inorganic  and 
Organic.     4th  Edition,  Revised.  .80;  Interleaved,  $1.00 

LEFFMANN.  Analysis  of  Milk  and  Milk  Products.  2d  Edition, 
Enlarged.     Illustrated.  $1.26 

LEFFMANN.  Water  Analysis.  For  Sanitary  and  Technio  Pur- 
poses.    Illustrated.     5th  Edition.  $1.25 

LEFFMANN.  Structural  Formulae.  Including  180  Structural 
and  Stereo-Chemical  Formulae.     12mo.     Interleaved.       $^.00 

LEFFMANN  AND  BEAM.  Select  Methods  in  Food  Analysis. 
Illustrated.  $2.50 

MUTER.  Practical  and  Analytical  Chemistry.  3d  American 
from  the  Ninth  English  Edition.  Revised  to  meet  the  re- 
quirements of  American  Students.     56  Illustrations.         $1.25 

OETTEL.     Exercises  in  Electro-Chemistry.    Illustrated.  .75 

OETTEL.     Electro-Chemical  Experiments.     Illustrated.  .75 

RICHTER.  Inorganic  Chemistry.  6th  American  from  10th 
German  Edition.  Authorized  translation  by  Edgak  F.  Smith, 
M.A  ,  PH.D.     89  Illustrations  and  a  Colored  Plate.  $1.76 

RICHTER.  Organic  Chemistry.  3d  American  Edition,  trans- 
lated from  the  8th  German  by  Edgar  F.  Smith.  Illus.  2  vols. 
Vol.    I.  Aliphatic  Series.     625  pages.  $3.00 

Vol.  II.  Carbocyclic  Series.     671  pages.  $3.00 

ROCKWOOD.  Chemical  Analysis  for  Students  of  Medicine, 
Dentistry,  and  Pharmacy.     Illustrated.  $1.50 

SMITH.     Electro-Chemical  Analysis.     3d  Ed.  39  Illus.     $1.50 
SMITH  AND  KELLER.     Experiments.     Arranged  for  Students 
in  General  Chemistry.    4th  Edition.    Illustrated.  .60 

SUTTON.  Volumetric  Analysis.  A  Systematic  Handbook  for 
the  Quantitative  Estimation  of  Chemical  Substances  by 
Measure,  Applied  to  Liquids,  Solids,  and  Gases.  8th  Edition, 
Revised.     112  Illustrations.  $5.00 

SYMONDS.     Manual  of  Chemistry.     2d  Edition.  $2.00 

TRAUBE.     Physico-chemical  Methods.    97  lUustrationt.    $1.60 


MEDICAL  BOOKS.  11 


THRESH.     Water  and  Water  Supplies.     3d  Edition.  $2.00 

ULZER    AND    FRAENKEL.        Chemical    Technical    Analysis. 

Translated  by  Fleck.     Illustrated.  $1.25 

WOODY.     Essentials  of  Chemistry  and  Urinalysis.    4th  Edition. 

Illustrated.  $1.50 

*♦*  Special  Catalogue  of  Books  on  Chemistry  free  upon  application. 

CHILDREN. 

HATFIELD.     Compend     of     Diseases     of     Children.     With     a 
Colored  Plate.    3d  Ed.    Just  Ready.        .80 ;  Interleaved,  $1.00 
IRELAND.     The   Mental  Affections  of   Children.     Idiocy,   Im- 
becility, Insanity,  etc.     2d  Edition.  $4.00 
POWER.     Surgical  Diseases  of  Children  and  their  Treatment 
by  Modern  Methods.     Illustrated.                                         $2.50 
STARR.     The  Digestive  Organs  in  Childhood.     The  Diseases  of 
the  Digestive  Organs  in  Infancy  and  Childhood.     3d  Edition, 
Rewritten  and  Enlarged.     Illustrated.  $3.00 
STARR.     Hygiene  of  the  Nursery.     Including  the  General  Regi- 
men and  Feeding  of  Infants  and  Children,  and  the  Domestic 
Management   of   the    Ordinary   Emergencies   of   Early   Life, 
Massage,  etc.     6th  Edition.     25  Illustrations.  $1.00 
SMITH.     Wasting  Diseases  of  Children.     6th  Edition.  $2.00 
TAYLOR  AND  WELLS.     The  Diseases  of  Children.     2d  Edition, 
Revised  and  Enlarged.     Illustrated.     8vo.                          $4.50 
"  It  is  well  worthy  the  careful  study  of  both  student  and  prac- 
titioner, and  can  not  fail  to  prove  of  great  value  to  both.     We 
do  not  hesitate  to  recommend  it." — Boston  Medical  and  Surgical 
Journal. 

DIAGNOSIS. 

BROWN.  Medical  Diagnosis.  A  Manual  of  Clinical  Methods. 
4th  Edition.     112  Illustrations.  Cloth,  $2.25 

DA  COSTA.  Clinical  Hematology.  A  Practical  Guide  to  Exam- 
ination of  Blood,  with  Reference  to  Diagnosis.  6  Colored 
Plates,  48  other  Illustrations.  Cloth,  $5.00 ;  Sheep,  $6.00 

DOUGLAS.  Surgical  Diseases  of  Abdomen,  with  Reference  to 
Diagnosis.     20  Full-Page  Plates.     Just  Ready. 

Cloth,  $7.00  ;  Sheep,  $8.00 

EMERY.  Bacteriological  Diagnosis.  2  Colored  Plates  and  32 
other  Illustrations.  $1.50 

MEMMINGER.    Diagnosis  by  the  Urine.    2d  Ed.    24  lUus.    $1.00 
PERSHING.     Diagnosis     of     Nervous     and     Mental     Diseases. 
Illustrated.  $1.25 

STEELL.     Physical  Signs  of  Pulmonary  Disease.  $1.25 

TYSON.  Handbook  of  Physical  Diagnosis.  For  Students  and 
Physicians.  By  the  Professor  of  Clinical  Medicine  in  the  Uni- 
versity of  Pennsylvania.  Illus.  4th  Ed.,  Improved  and  En- 
larged.   With  2  Colored  and  55  other  Illustrations.  $1.50 

DENTISTRY. 

Special  Catalogue  of  Dental  Book*  tent  free  upon  application. 
BARRETT.     Dental    Surgery    for    General    Practitioners    and 
Students  of  Medicine  and  Dentistry.     Extraction  of  Teeth, 
eta.     3d  Edition.     Illustrated.  $1.00 


12  SUBJECT  CATALOGUE. 

BROOMELL.  Anatomy  and  Histology  of  the  Human  Mouth 
and  Teeth.  Second  Edition,  Revised  and  Enlarged.  337 
handsome  Illustrations.  Cloth,  $4.50;  Leather,  $5.50 

FILLEBROWN.     Operative  Dentistry.    Illustrated.  $2.26 

GORGAS.  Dental  Medicine.  A  Manual  of  Materia  Medica  and 
Therapeutics.     7th  Edition.  Cloth,  $4.00 ;  Sheep,$5.00 

GORGAS.  Questions  and  Answers  for  the  Dental  Student. 
Embracing  all  the  subjects  in  the  Curriculum  of  the  Dental 
Student.     Octavo.  $6.00 

HARRIS.  Principles  and  Practice  of  Dentistry.  Including 
Anatomy,  Physiology,  Pathology,  Therapeutics,  Dental  Sur- 
gery, and  Mechanism.  13th  Edition.  Revised  by  F.  J.  S. 
GoRGAS,  M.D.,  D.D.s.     1250  Illus.    Cloth.  $6.00 ;  Leather,  $7.00 

HARRIS.  Dictionary  of  Dentistry.  Including  Definitions  of  Such 
Words  and  Phrases  of  the  Collateral  Sciences  as  Pertain  to  the 
Art  and  Practice  of  Dentistry.  6th  Edition,  Revised  and 
Enlarged  by  Ferdinand  J.  S.  Goroas,  m.d.,  ^.s.b. 

Cloth,  $5.00;  Leather.  $6.00 

RICHARDSON.  Mechanical  Dentistry.  7th  Edition.  Thor- 
oughly Revised  and  Enlarged  by  Dk.  Gho.  W.  Warrbn.  691 
Illustrations.  Cloth,  $5.00;  Leather,  $6.00 

SMITH.     Dental  Metallurgy.    2d  Edition.    Illustrated.  $2.00 

TAFT.    Index  of  Dental  Periodical  Literature.  $2.00 

TOMES.     Dental  Anatomy.     263  Illustrations.     6th  Ed.  $4.00 

TOMES.     Dental  Surgery.    4th  Edition.    289  Illu».  $4.00 

WARREN.  Compend  of  Dental  Pathology  and  Dental  Medicine. 
With  a  Chapter  on  Emergencies.      th  Edition.    Illustrated. 

.80;  Interleaved,  $1.00 
WARREN.  Dental  Prosthesis  and  Metallurgy.  129  Illus.  $1.25 
WHITE.    The  Mouth  and  Teeth.     Illustrated.  .40 

DICTIONARIES.     CYCLOPEDIAS. 

GOULD.  The  Illustrated  Dictionary  of  Medicine,  Biology,  and 
Allied  Sciences.  Being  an  Exhaustive  Lexicon  of  Medicine  and 
those  Sciences  Collateral  to  it:  Biology  (Zoology  and  Botany), 
Chemistry,  Dentistry,  Pharmacology,  Microscopy,  etc.,  with 
many  useful  Tables  and  numerous  fine  Illustrations.  1633 
pages.     Fifth  Edition.     ^ 

Sheep  or  Half  Morocco.  $10.00:  with  Thumb  Index,  $11.00 
Half  Russia,  Thumb  Index,  $12.00 
GOULD.  The  Medical  Student's  Dictionary,  nth  Edition.  Il- 
lustrated. Including  those  Words  and  Phrases  generally  used 
in  Medicine,  with  their  Proper  Pronunciation  and  Definition, 
Based  on  Recent  Medical  Literature.  With  Table  of  Epo- 
nymio  Terms  and  Tests  and  Tables  of  the  Bacilli,  Micrococci, 
Mineral  Springs,  etc.,  of  the  Arteries,  Muscles,  Nerves,  Ganglia, 
Plexuses,  etc.  Eleventh  Edition.  Enlarged  and  illustrated 
with  a  large  number  of  Engravings.    840  pages. 

Half  Morocco,  $2.50 ;  with  Thumb  Index,  $3.00 
FlexibleXeather,  Burnished  Edges,  Thumb  Index,    3.50 


MEDICAL  BOOKS.  13 


GOULD.  The  Pocket  Pronoxincing  Medical  Lexicon.  4th  Edi- 
tion. (30,000  Medical  Words  Pronounced  and  Defined.)  Con- 
tainine  all  the  Words,  their  Definition  and  Pronunciation, 
that  the  Medical,  Dental,  or  Pharmaceutical  Student  Gener- 
ally Comes  in  Contact  with;  also  Elaborate  Tables  of  Epo- 
nynr\io  Terms,  Art«rie9,  Muscles,  Nerves,  Bacilli,  etc.,  etc.,  a 
Dose  List  in  both  Englinh  and  Metric  Systems,  etc..  Arranged 
in  a  Most  Convenient  Form  for  Reference  and  Memorising. 
Fourth  Edition,  Reviaed  and  Enlarged.  838  pages. 
Full  Limp  Leather,  Gilt  Edges,  $1.00;  Thumb  Index,  $1.25 
145,000  Copies  of  Gould's  Dictionaries  have  been  sold. 

GOULD  AITD  PYLE.  Cyclopedia  of  Practical  Medicine  and 
Surgery.  Seventy-two  Special  Contributors.  Illustrated.  One 
Volume.  A  Concise  Reference  Handbook  of  Medicine,  Sur- 
gery, Obstetrics,  Materia  Medica,  Therapeutics,  and  the  Vari- 
ous Specialties,  with  Particular  Reference  to  Diagnosis  and 
Treatment.  CompUed  under  the  Editorial  Supervision  of 
GaoRQB  M.  Gould,  m.©..  Author  of  "An  Illustrated  Dictionary 
of  Medicine,"  etc.;  and  WjLltkr  L.  Ptlb,  m.d.,  Assistant 
Surgeon  Wills  Eye  Hospital;  formerly  Editor  "International 
Me<£cal  Magasine,"  etc.,  and  Seventy-two  Special  Contribu- 
tors. With  many  Illustrations.  Large  Square  8vo,  to  corre- 
spond with  Gould's  "Illustrated  Dictionary." 
Full  Sheep  or  Half  Mor.,  $10.00;  with  Thumb  Index,  $11.00 
Half  Russia,  Thumb  Index,  $12.00  net. 

GOULD  AKD  PYLE.  Pocket  Cyclopedia  of  Medicine  and  Sur- 
gery. Based  upon  above  book  and  uniform  in  size  with 
"Gould's  Pocket  Dictionary." 

FuU  Limp  Leather,  GUt  Edges,  $1.00 
With  Thumb  Index,  $1.25 

HARRIS.  Dictionary  of  Dentistry.  Including  Definitions  of 
Such  Words  and  Phrases  of  the  Collateral  Sciences  as  Pertain 
to  the  Art  and  Practice  of  Dentistry.  6th  Edition,  Revised 
and  Enlarged  by  Fkbdinand  J.  S.  Gorgas,  m.d.,  d.d.s. 

Cloth,  $5.00:  Leather,  $6.00 

LONGLEY.     Pocket  Medical  Dictionary.  Cloth,  .75 

TREVES  AITD  LANG.     German-English  Medical  Dictionary. 

Half  Calf,  $3.25 

DIET  AND  FOOD. 

ALLEN.  Proteids  and  Albuminous  Principles.  An  analytical 
Study  of  Food  Products.     2d  Edition.  $4.50 

BURNETT.  Foods  and  Dietaries.  A  Manual  of  Clinical  Diet- 
etics, with  Diet  Lists  for  Various  Diseases,  etc.     2d  Ed.     $1.50 

DAVIS.  Dietotherapy.  Food  in  Health  and  Disease.  With 
Tables  of  Dietaries,  Relative  Value  of  Foods,  etc.  See  Cohen, 
Phyaiologic  Therapeutic*,  page  17. 

GREENISH.     Microscopical  Examination  of  Foods  and  Drugs. 

Illustrated.     Just  Ready.  $3.50 

HAIG.  Diet  and  Food.  Considered  in  Relation  to  Strength  and 
Power  of  Endurance.     4th  Edition.  $1.00 

LEFFMANN.     Select  Methods  in  Food  Analysis.     Ulua.         $2.50 


14  SUBJECT  CATALOGUE. 

EAR  (see  also  Throat  and  Nose). 

BURNETT.     Hearing  and  How  to  Keep  It.     Illustrated.  .40 

HOVELL.  Diseases  of  the  Ear  and  Naso-Pharynx.  Including 
Anatomy  and  Physiology  of  the  Organ,  together  with  the 
Treatment  of  the  Affections  of  the  Nose  and  Pharynx  which 
Conduce  to  Aural  Disease.  128  Illustrations.  2d  Ed.  $5.50 
PRITCHARD.  Diseases  of  the  Ear.  4th  Edition,  Enlarged. 
Many  Illustrations  and  For/nul£e.  In  Press. 

ELECTRICITY. 

BIGELOW.     Plain  Talks  on  Medical  Electricity  and  Batteries. 

With  a  Therapeutic  Index  and  a  Glossary.     43  Illustrations. 

2d  Edition.  $1.00 

HEDLEY.     Therapeutic  Electricity  and  Practical  Muscle  Testing. 

99  Illustrations.  $2.50 

JACOBY.     Electrotherapy.    2  volumes.    Illustrated.    See  Cohen, 

Physiologic  Therapeutics,  page  17. 
JONES.     Medical  Electricity.     3d  Edition.     117  lUus.        $3.00 

EYE. 

A  Special  Circular  of  Books  on  the  Eye  sent  free  upon  application. 

DARIER.     Ocular  Therapeutics.     Just  Beady.  $3.00 

DONDERS.     The   Nature   and   Consequences   of  Anomalies   of 

Refraction.     With  Portrait  and  lUus.         Half  Morocco,  $1.25 

FICK.  Diseases  of  the  Eye  and  Ophthalmoscopy.  Translated 
by  A.  B.  Halb,  M.D.     157  Illus.     Cloth,  $4.50;   Sheep,  $5.50 

GOULD  AND  PYLE.  Compend  of  Diseases  of  the  Eye  and  Re- 
fraction. Including  Treatment  and  Operations,  and  a  Section 
on  Local  Therapeutics.  With  Formulae,  Usefiil  Tables,  %. 
Glossary,  and  111  Illus.,  several  of  which  are  in  colors.  2d 
Edition,  Revised.  Cloth,  .80;  Interleaved,  $1.00 

GREEFF.  The  Microscopic  Examination  of  the  Eye.  Illus- 
trated. $1.25 

HARLAN.     Eyesight,  and  How  to  Care  for  It.     Illus.  .40 

HARTRIDGE.  On  the  Ophthahnoscope.  4th  Edition.  With 
4  Colored  Plates  and  68  Wood-cuts.  $1.60 

HARTRIDGE.  Refraction.  104  Illustrations  and  Test  Types. 
12th  Edition,  Enlarged.  $1.50 

HANSELL  AND  SWEET.  Treatise  on  Diseases  of  the  Eye. 
With  253  Illustrations.  $4.00 

HANSELL  AND  REBER.  Muscular  Anomalies  of  the  Eye. 
Illustrated.  $1.50 

HANSELL  AND  BELL.  Clinical  Ophthalmology.  Colored 
Plate  of  Normal  Fundus  and  120  Illustrations.  $1.50 

HENDERSON.     Notes  on  the  Eye.     3d  Ed.    Just  Ready.    $1.50 

JENNINGS.  Manual  of  Ophthalmoscopy.  95  Illustrations  and 
1  Colored  Plate.  $1.50 

MORTON.  Refraction  of  the  Eye.  Its  Diagnosis  and  the  Cor- 
rection of  its  Errors.     6th  Edition.  $1.00 

OHLEMANN.  Ocular  Therapeutics.  Authorized  Translation, 
and  Edited  by  Dr.  Charles  A.  Olivbr.  $1.76 

PARSONS.  Elementary  Ophthalmic  Optics.  With  Diagram- 
matio  Illustrations.  $2.00 


MEDICAL  BOOKS.  15 


PHILLIPS.     Spectacles     and     Eyeglasses.     Their     Prescription 

and  Adjustment.     3d  Edition.     52  Illustrations.  $1.00 

SWANZY.     Diseases   of   the    Eye    and   Their   Treatment.     8th 

Edition,  Revised  and  Enlarged.     168   Illustrations,    1  Plain 

Plate  and  a  ZephjT  Test  Card.     Just  Ready.  $2.50 

THORINGTON.     Retinoscopy.     4th  Edition,  Carefully  Revised. 

Illustrated.  $1.00 

THORINGTON.     Refraction  and  How  to  Refract.     200  lUustra- 

tions,  13  of  which  are  colored.     2d  Edition.  $1.50 

WALKER.     Student's   Aid    in    Ophthabnology.     Colored   Plate 

and  40  other  Illustrations  and  a  Glossary.  $1.50 

WORTH.  Squint :  Its  Causes,  Pathology,  Treatment.  $2.00 
WRIGHT.     Ophthalmology.     2d  Edition,  Revised  and  Enlarged. 

117  Illustrations  and  a  Glossary.  $3.00 

FEVERS. 

GOODALL  AND  WASHBOURN.     Fevers  and  Their  Treatment. 

Illustrated.  $3.00 

WILCOX.     Fever  Nursing.  In  Press. 

GYNECOLOGY. 

BISHOP.  Uterine  Fibromyomata.  Their  Pathology,  Diag- 
nosis, and  Treatment.     Illustrated.  Cloth,  $3.50 

BYFORD  (H.  T.).  Manual  of  Gynecology.  3d  Edition,  Revised 
and  Enlarged.     363  Illustrations.  S3.00;  Sheep,  $3.50 

DtJHRSSEN.  A  Manual  of  Gynecological  Practice.  105  Illus- 
trations. $1.50 

FTJLLERTON.  Surgical  Nursing.  3d  Edition,  Revised  and 
Enlarged.     69  Illustrations.  $1.00 

GALABIN.  Diseases  of  Women.  Sixth  Edition.  By  Alfred 
Lewis  Galabin,  m.a.,  m.d.,  f.r.c.p.  6th  Edition,  Revised 
and  Enlarged.     284  Illustrations.     Octavo.  Cloth,  $5.00 

LEWERS.     Diseases  of  Women.     146  Illus.     5th  Ed.  $2.50 

LEWERS.     Cancer  of  the  Uterus.     Jitst  Ready.  $3.00 

MONTGOMERY.  Practical  Gynecology.  A  Complete  Sys- 
tematic Text-Book.  2d  Edition,  Revised  and  Enlarged. 
With  539  Illus.     Just  Ready.        Cloth,  $5.00;  Leather,  $6.00 

ROBERTS.  Gynecological  Pathology.  With  127  Full-page 
Plates  containing  151  Figures.  $6.00 

WELLS.  Compend  of  Gynecology.  Illustrated.  3d  Edition, 
Revised  and  Enlarged.     Just  Ready.     .80;  Interleaved,  $1.00 

HEART. 

THORNE.  The  Schott  Methods  of  the  Treatment  of  Chronic 
Heart  Disease.     Fourth  Edition.     Illustrated.  $2.00 

HISTOLOGY. 

GUSHING.  Compend  of  Histology.  By  H.  H.  Cushino,  m.d., 
Demonstrator  of  Histology,  Jefferson  Medical  College,  Phila- 
delphia.    Illus.     Nearly  Ready.  .80;  Interleaved,  $1.00 

LAZARUS-BARLOW.  Pathological '  Anatomy  and  Histology. 
Uluatrated.     Just  Ready.  $6.50 


1«  SUBJECT  CATALOGUE. 

STIRLING.  Outlines  of  Practical  Histology.  368  Illxistrationg. 
2d  Edition,  Revised  and  Enlarged.     With  new  Illua.        $2.00 

STOHR.  Histology  and  Microscopical  Anatomy.  Edited  by 
A.  ScHAPBR,  M.D.,  University  of  Breslau,  formerly  Demon- 
strator of  Histology,  Harvard  Medical  School.  Fifth  Amer- 
ican from  10th  German  Edition,  Revised  and  Enlarged.  353 
nivistrations.  $3.00 

HYGIENE. 

Special  Catalogue  of  Books  on  Hygiene  sent  free  upon  application. 

CAIfFIELD.  Hygiene  of  the  Sick-Room.  A  Book  for  Nurses 
and  Others.  Being  a  Brief  Consideration  of  Asepsis,  Anti- 
sepsis, Disinfection,  Bacteriology,  Immunity,  Heating,  Venti- 
lation, etc.  $1.25 

CONN.     Agricultural  Bacteriology.     Illxistrated.  $2.50 

CONN.     Bacteriology  of  Milk  and  Milk  Products-     Hlus.    $1.26 
COPLIN.     Practical    Hygiene.     A    Complete    American    Text- 
Book.     138  Illustrations.     New  Edition.  Preparing. 
HARTSHORNE.     Our  Homes.     Illustrated.  .40 
KENWOOD.     PubUc  Health  Laboratory  Work.     116  Illustra- 
tions and  3  Plates.                                                                    $2.00 
LEFFMANN.     Select  Methods  in  Food  Analysis.     53  Illustra- 
tions and  4  Plates.                                                                    $2.50 
LEFFMANN.     Examination  of  Water  for  Sanitary  and  Technical 
Purposes.     4th  Edition.     Illustrated.                                   $1.25 

LEFFMANN.     Analysis  of  Milk  and  Milk  Products.     Illustrated. 

Second  Edition.  $1.25 

LINCOLN.     School  and  Industrial  Hygiene.  .40 

McFARLAND.     Prophylaxis    and    Personal    Hygiene.     CSare   of 

the  Sick.     See  Cohen,  Physiologic  TherapeiUics,  page  17. 

KOTTER.  The  Theory  and  Practice  of  Hygiene.  15  Plates  and 
138  other  Illustrations.     8vo.     2d  Edition.  $7.00 

PARKAS  AND  KENWOOD.  Hygiene  and  PubUc  Health.  2d 
Edition,  Enlarged.     Illustrated.  $3.00 

ROSENAU.     Disinfection  and  Disinfectants.     Hlus.  $2.00 

STARR.  The  Hygiene  of  the  Nursery.  Including  the  General 
Regimen  and  Feeding  of  Infants  and  Children,  and  the  Domes- 
tic Management  of  the  Ordinary  Emergencies  of  Early  Life, 
Massage,  etc.     6th  Edition.     25  Illustrations.  $1.00 

STEVENSON  AND  MURPHY.  A  Treatise  on  Hygiene.  By 
Various  Authors.     In  three  octavo  volumes.     Illustrated. 

Vol.  I,  $6.00;  Vol.  II,  $6.00;  Vol.  Ill,  $5.00 

THRESH.     Water  and  Water  Supplies.     3d  Edition.  $2.00 

WILSON.  Handbook  of  Hygiene  and  Sanitary  Science.  With 
Illustrations.     8th  Edition.  $3.00 

WEYL.  Sanitary  Relations  of  the  Coal-Tar  Colors.  Authorised 
Translation  by  Hbnbt  Lsffuann,  ii.J>.,  ph.d.  $1.25 

LUNGS  AND  PLEURA. 

KNOPF.  Pulmonary  Tuberculosis.  Its  Modem  Prophylaxis  and 
Treatment  in  Special  Institutions  and  at  Home.    lUus.    $3.00 

STEELL.     Physical  Signs  of  Pulmonary  Disease.     Illua.       $1.25 


MEDICAL  BOOKS.  17 


MASSAGE.     PHYSICAL  EXERCISE. 

OSTROM.  Massage  and  the  Orieinal  Swedish  Movements. 
Their  Application  to  Various  Diseases  of  the  Body.  A  Manual 
for  Students,  Nurses,  and  Physicians.  Fifth  Edition,  En- 
larged.    115  Illustrations,  many  of  which  are  original.     $1.00 

MITCHELL  AND  GULICK.  Mechanotherapy.  Exercise,  Ortho- 
pedics, Massage,  Ocular  Corrections,  etc.  Illustrated.  Set 
Cohen,  Phytiologie    Therapeutics,  below. 

TREVES.     Physical  Education.     Its  Value,  Methods,  etc.        .76 

MATERIA  MEDICA  AND  THERAPEUTICS. 

BRACKEN.  Outlines  of  Materia  Medica  and  Pharmacology.  $2.75 
COBLENTZ.     The  Newer  Remedies.     Including  their  Synonyms, 
Sources,  Methods  of  Preparation,  Tests,  Solubilities,  Doses, 
etc.     3(1  Edition,  Enlarged  and  Revised.  $1.00 

COHEN.  Physiologic  Therapeutics.  Methods  other  than  Drug- 
Giving  useful  in  the  Prevention  of  Disease  and  in  the  Treat- 
ment of  the  Sick.  Mechanotherapy,  Mental  Therapeutics, 
Suggestion,  Electrotherapy,  Climatology,  Hydrotherapy, 
Pneumatotherapy,  Prophylaxis,  Dietetics,  Organotherapy, 
Phototherapy,  Mineral  Waters,  Baths,  etc.  11  volumes,  8vo. 
Illustrated.     (Subscription.)  Cloth,  $27.50;  ^  Mor.,  $38.50 

Special  Descriptive  Circular  toill  be  tent  upon  application. 

GORGAS.  Dental  Medicine.  A  Manual  of  Materia  Medica  and 
Therapeutics.     7th  Edition,  Revised.  $4.00 

GROFF.  Materia  Medica  for  Nurses,  with  Questions  for  Self- 
Examination.     2d  Edition,  Revised  and  Improved.  $1.25 

HELLER.  Essentials  of  Materia  Medicat  Pharmacy,  and  Pre- 
scription Writing.  $1.50 

HEWLETT.     Serum-Therapy.  $1.75 

MAYS.     Theine  in  the  Treatment  of  Neuralgia,     i  bound.        .60 
POTTER.     Handbook  of  Materia  Medica,  Pharmacy,  and  Thera- 
peutics, including  the  Action  of  Medicines,  Special  Therapeu- 
tics, Pharmacology,  etc.,  including  over  600  Prescriptions  and 
Formulae.     9th  Edition,  Revised  and  Enlarged.     With  Thumb 
Index  in  each  copy.     Just  Ready.      Cloth,  $5.00 ;  Sheep,  $6.00  ' 
"In  conclusion  we  may  add  that  Dr.  Potter's  Therapeutics 
covers  a  wider  field  than  many  books  which  bear  this  title.    He 
discusses  a  good  many  drugs  which  are  rarely  employed,  and 
therefore  the  book  is  as  useful  to  one  who  wishes  to  look  for  un- 
usual information  as  it  is  to  him  who  wishes  a  handbook  for  ready 
reference  in  the  treatment  of  disease  as  he  meets  it  from  day  to 
day." — Therapeutic  Gazette. 

POTTER.  Compend  of  Materia  Medica,  Therapeutics,  and  Pre- 
scription Writing,  with  Special  Reference  to  the  Physiological 
Action  of  Drugs.     6th  Edition.  .80;  Interleaved,  $1.00 

MURRAY.     Rough  Notes  on  Remedies.     4th  Edition.  $1.25 

SAYRE.  Organic  Materia  Medica  and  Pharmacognosy.  An 
Introduction  to  the  Study  of  the  Vegetable  Kingdom  and  the 
Vegetable  and  Animal  Drugs.  Comprising  the  Botanical  and 
Physical  Characteristics,  Source,  Constituents,  and  Pharma- 
copeial  Preparations,  Insects  Injurious  to  Drugs,  and  Pharma- 
cal  Botany.  With  sections  on  Histology  and  Microtechnique, 
by  W.  C.  St«tbn8.  374  Illustrations,  many  of  which  are 
original.     2d  Edition.  Cloth,  $4.60 


18  SUBJECT  CATALOGUE. 

TAVERA.     Medicinal  Plants  of  the  Philippines.  S2.00 

WHITE  AND  WILCOX.  Materia  Medica,  Pharmacy,  Pharma- 
cology, and  Therapeutics.  5th  American  Edition,  Revised  by 
Reynold  W.  Wilcox,  m.a.,  m.d.,  ll.d.,  Professor  of  Clinical 
Medicine  and  Therapeutics  at  the  New  York  Post-Graduate 
Medical  School.  Cloth,  $3.00 ;  Leather,  $3.50 

MEDICAL  JURISPRUDENCE  AND 
TOXICOLOGY. 

REESE.  Medical  Jiirisprudence  and  Toxicology.  A  Text-Book 
for  Medical  and  Legal  Practitioners  and  Students.  6th 
Edition.     Revised  by  Henry  Leffmann.  m.d. 

Cloth,  $3.00 ;  Leather,  $3.50 

"To  the  student  of  medical  jurisprudence  and  toxicology  it  is 
invaluable,  as  it  is  concise,  clear,  and  thorough  in  every  respect." 
— The  American  Journal  of  the  Medical  Sciences. 

MANN.     Forensic  Medicine  and  Toxicology.     Illua.  S6.50 

TANNER.     Memoranda  of  Poisons.     Their  Antidotes  and  Tests. 

9th  Edition,  by  Dr.  Henry  Leffmann.     Just  Ready.         .75 

MICROSCOPY. 

CARPENTER.  The  Microscope  and  Its  Revelations.  8th 
Edition,  Revised  and  Enlarged.  817  Illustrations  and  23 
Plates.  Cloth,  $8.00;  Half  Morocco,  $9.00 

GREENISH.  Microscopical  Examination  of  Foods  and  Drugs. 
Illvistrated.     Just  Ready.  $3.50 

LEE.  The  Microtomist's  -  Vade  Mecum.  A  Handbijok  of 
Methods  of  Microscopical  Anatomy.  887  Articles.  5th 
Edition,  Enlarged.  $4.00 

OERTEL.  Medical  Microscopy.  A  Guide  to  Diagnosis,  Ele- 
mentary Laboratory  Methods  and  Microscopic  Technic.  131 
Illustrations.  $2.00 

REEVES.  Medical  Microscopy,  including  Chapters  on  Bacteri- 
ology, Neoplasms,  Urinary  Examination,  etc.  Numerous 
Illustrations,  some  of  which  are  printed  in  colors.  $2.50 

WETHERED.  Medical  Microscopy.  A  Guide  to  the  Use  of  the 
Microscope  in  Practical  Medicine.     100  Illustrations.        $2.00 

MISCELLANEOUS. 

BERRY.     Diseases  of  Thyroid  Gland.     Illustrated.  $4.00 

BUXTON.     Anesthetics.     Illustrated.     3d  Edition.  $1.50 

COHEN.     Organotherapy.    See  Cohen,  Physiologic  Therapeutics, 

page  17. 
FRENKEL.     Tabetic  Ataxia.     Illustrated.  $3.00 

GOULD.  Borderland  Studies.  Miscellaneous  Addresses  and 
Ewaye.     12mo.  $2.00 

GOULD.  Biographic  Clinics.  Volume  I.  The  Origin  of  the 
Ill-Health  of  DeQuincy,  Carlyle,  Darwin,  Huxley,  and 
Browning.  $1.00 


MEDICAL  BOOKS.  19 

GOULD      Biographic  Clinics.     Volume  II.     The  Origin  of  the 
Ill-Health    of    Wagner,    Parkman,    Mrs.    Carlisle,    Spencer, 
Whittier,  Ossoli,  George  Eliot,  and  Nietsche.     Nearly  Ready. 
GREENE.     Medical    Examination    for    Life    Insurance.     IUub. 
With  colored  and  other  Engravings.     2d  Edition.       In  Press. 
ELAIG.     Causation  of  Disease  by  Uric  Acid.     The  Pathology  of 
High  Arterial  Tension,  Headache,  Epilepsy,  Gout,  Rheuma- 
tism, Diabetes,  Bright's  Disease,  etc.     6th  Edition.         $3.50 
HENRY.     A  Practical  Treatise  on  Anemia.  Half  Cloth,  .50 

NEW  SYDENHAM  SOCIETY'S  PUBLICATIONS.  Circulars 
upon  application.  Per  Annum,  $8.00 

OSGOOD.     The  Winter  and  Its  Dangers.  .40 

PACKARD.     Sea  Air  and  Sea  Bathing.  .40 

RICHARDSON.     Long  Life  and  How  to  Reach  It.  .40 

SCHEUBE.  Diseases  of  Warm  Countries.  Illustrated.  Just 
Ready.  $8.00 

TISSIER.     Pneumotherapy,    Aerotherapy,  Inhalation  Methods. 

See  Cohen,    Physiologic  Therapeutics,  page  17. 
TURNBULL.     Artificial  Anesthesia.     4th  Ed.     Illus.  $2.50 

WARDEN.     The  Paris  Medical  SchooL  Paper,    75 

WEBER  AND  HINSDALE.     CUmatology  and  Health  Resorts. 
Including  Mineral  Springs.     2  vols.     Illustrated  with  Colored 
Maps.     See  Cohen,  Physiologic  Therapeutics,  page  17. 
WILSON.     The  Simimer  and  Its  Diseases.  .40 

WINTERNITZ.  Hydrotherapy,  Thermotherapy,  Phototherapy, 
Mineral  Waters,  Baths,  etc.  Illustrated.  See  Cohen,  Physio- 
logic Therapeutics,  page  17. 

NERVOUS  DISEASES. 

DERCUM.  Rest,  Suggestion,  Mental  Therapeutics.  See  Cohen, 
Physiologic  Therapeutics,  page  17. 

GORDINIER.  The  Gross  and  Minute  Anatomy  of  the  Central 
Nervous  System.  With  271  original  colored  and  other  Illus- 
trations. Cloth,  $6.00;  Sheep,  $7.00 

GOWERS.     Syphilis  and  the  Nervous  System.  $1.00 

GOWERS.     Manual   of   Diseases   of   the    Nervous   System.     A 
Complete  Text-Book.     Revised,  Enlarged,  and  in  many  parts 
Rewritten.     With  many  new  Illustrations.     Two  volumes. 
Vol.  I.  Diseases  of  the  Nerves  and  Spinal  Cord.     3d  Edition, 
Enlarged.  Cloth,  $4.00;  Sheep,  $5.00 

Vol.  II.  Diseases  of  the  Brain  and  Cranial  Nerves;  General  and 
Functional  Disease.     2d  Ed.         Cloth,  $4.00 ;  Sheep,  $5.00 

GOWERS.  Epilepsy  and  Other  Chronic  Convulsive  Diseases. 
2d  Edition.  $3.00 

GOWERS.     Clinical  Lectures.     Illustrated.     Second  Series." 

^_  iTt  PT€SS 

HORSLEY.  The  Brain  and  Spinal  Cord,  the  Structure  and 
Functions  of.     Numerous  Illustrations.  $2.50 

ORMEROD.  Diseases  of  the  Nervous  System.  66  Wood  En- 
gravmgs.  $1.00 

PERSHING.  Diagnosis  of  Nervous  and  Mental  Diseases.  Illus- 
trated. J1.25 

PRESTON.     Hysteria    and    Certain    AUied    Conditions,     Their 

Nature  and  Treatment.     Illustrated.  $2.00 

WOOD.     Brain  Work  and  Overwork.  .40 


20  SUBJECT  CATALOGUE. 

NURSING  (see  also  Massage). 

Special  Cataloffue  of  Bookt  for  Nurse*  tent  free  upon  application. 

CASTIELD.  Hygiene  of  the  Sick-Room.  A  Book  for  Nurses 
and  Others.  Being  a  Brief  Consideration  of  Asepsis,  Anti- 
sepsis, Disinfection,  Bacteriology,  Immunity,  Heating  and 
Ventilation,  and  Kindred  Subjects  for  the  Use  of  Nurses  and 
Other  Intelligent  Women.  S1.25 

CUFF.     Lectiu-es  to  Nurses  on  Medicine.    4th  Edition.        $1.25 

DAVIS.  Bandaging.  Its  Principles  and  Practice.  163  Original 
Illustrations.  S1.50 

DOMVILLE.  Manual  for  Nurses  and  Others  Engaged  in  At- 
tending the  Sick.  9th  Edition.  With  Recipes  for  Sick-room 
Cookery,  etc.  In  Press. 

FULLERTON.     Obstetric  Nursing.     6th  Ed.  45  Illua.         $1.00 

FULLERTON.     Surgical  Nursing.     3d  Ed.     69  Illus.  $1.00 

6R0FF.  Materia  Medica  for  Nurses.  With  Questions  for  Self- 
Examination.  2d  Edition,  Revised  and  Improved-  Just 
Ready.  $1.25 

HADLEY.  Generalf  Medical,  and  Surgical  Nursing.  A  very 
Complete  Manual,  Including  Sick-room  Cookery.  $1.25 

HUMPHREY.  A  Manual  for  Nurses.  Including  General 
Anatomy  and  Physiology,  Management  of  the  Sick-room,  etc. 
24th  Edition.     79  Illustrations.  $1.00 

STARR.  The  Hygiene  of  the  Nursery.  Including  the  General 
Regimen  and  Feeding  of  Infants  and  Children,  and  the  Domes- 
tic Management  of  the  Ordinary  Emergencies  of  Early  Life, 
Massage,  etc.     6th  Edition.     25  Illustrations.  $1.00 

TEMPERATURE  AND  CLINICAL  CHARTS.     See  page  25. 

VOSWINEJSL.  Surgical  Nursing.  Second  Edition,  Enlarged. 
112  lUustrations.  $1.00 

WILCOX.     Fever  Nursing.  Preparing. 

OBSTETRICS. 

CAZEAUX  AND  TARNIER.  Midwifery.  With  Appendix  by 
MuNDi).  The  Theory  and  Practice  of  Obstetrics,  including  the 
Diseases  of  Pregnancy  and  Partvu-ition,  Obstetrical  Operations, 
etc.  8th  Edition.  Illustrated  by  colored  and  other  full-page 
Plates,  and  numerous  Wood  Engravings. 

Cloth,  $4.50;  Full  Leather,  $6.50 

EDGAR.  Text-Book  of  Obstetrics.  By  J.  Cufton  Edgar, 
M.D.,  Professor  of  Obstetrics  and  Clinical  Midwifery,  Medical 
Department  of  Cornell  University,  New  York  City,  etc.  1221 
Illustrations.    Just  Beady.  Cloth,  $6.00;  Sheep,  $7.00 

FULLERTON.     Obstetric  Nursing.     6th  Ed.     lUus.  $1.00 

LANDIS.  Compend  of  Obstetrics.  7th  Edition,  Revised  by 
Wm.  H.  Wmxs,  M.D.,  Demonstrator  of  Clinical  Obstetrics. 
Jefferson  Medical  College.     52  Illustrations. 

.80;  Interleaved,  $1.00 

WINCKEL.  Text-Book  of  Obstetrics,  Including  the  Pathology 
and  Therapeutics  of  the  Puerperal  State.     Illustrated.      $5.00 

PATHOLOGY. 

BLACKBURN.  Autopsies.  A  Manual  of  Autopsies  Designed 
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COPLIN.  Manual  of  Pathology.  Including  Bacteriology,  Tech- 
nic  of  Post-Mortems,  Methods  of  Pathologic  Research,  etc. 
330  Illuatrationa,  7  Colored  Platea.     3d  Edition.  $3.50 

DA  COSTA.  Clinical  Hematology.  A  Practical  Guide  to  the 
Examination  of  the  Blood.  Six  Colored  Plates  and  48  Illus- 
trations. Cloth,  $5.00;  Sheep,  $6.00 

LAZARUS-BARLOW.  Pathological  Anatomy.  With  7  Colored 
Plates  and  171  other  Illustrations.  $6.50 

MacLEOD.  The  Pathology  of  the  Skin.  Colored  and  other 
Illustrations.     Just  Ready.  $5.00 

MARTIN.     Manual  of  Pathology.     Illustrated.     Nearly  Ready. 

ROBERTS.     Gynecological  Pathology.     Illustrated.  $6.00 

THAYER.     Compend  of  Special  Pathology.     Illustrated. 

.80;  Interleaved,  $1.00 

THAYER.  Manual  of  General  and  Special  Pathology.  131 
Illustrations.     711  pages.     2d  Edition.     Just  Ready.      $2.50 

VIRCHOW.     Post-Mortem  Examinations.     3d  Edition.  .75 

WHITACRE.  Laboratory  Text-Book  of  Pathology.  With  121 
Illustrations.  $1.50 

PHARMACY, 

Special  Catalogue  of  Book*  on  Pharmacy  sent  free  upon  application. 

COBLENTZ.  Manual  of  Pharmacy.  A  Complete  Text-Book  by 
the  Professor  in  the  New  York  College  of  Pharmacy.  2d  Ed., 
Revised  and  Enlarged.     437  Illus.     Cloth,  $3.50;  Sheep,  $4.50 

COBLENTZ.     Volxmietric  Analysis.     Illustrated.  $1.25 

BEASLEY.  Book  of  3100  Prescriptions.  Collected  from  the 
Practice  of  the  Most  Eminent  Physicians  and  Surgeons — Eng- 
lish, French,  and  American.  A  Compendious  History  of  the 
Materia  Medica,  Lists  of  the  Doses  of  all  the  Officinal  and  Es- 
tablished Preparations,  an  Index  of  Diseases  and  their  Reme- 
dies.    7th  Edition.  $2.00 

BEASLEY.  Druggists'  General  Receipt  Book.  Comprising  a 
Copious  Veterinary  Formulary,  Recipes  in  Patent  and  Pro- 
prietary Medicines,  Druggists'  Nostrums,  etc. ;  Perfumery  and 
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Chemicals,  Soientifio  Processes,  and  many  Useful  Tables. 
10th  Edition.  $2.00 

BEASLEY.  Pharmaceutical  Formulary.  A  Synopsis  of  the 
British,  French,  German,  and  United  States  Pharmacopoeias. 
Comprising  Standard  and  Approved  Formulae  for  the  Prepara- 
tions and  Compounds  Employed  in  Medicine.    12th  Ed.  $2.00 

GREENISH.  Microscopical  Examination  of  Foods  and  Drugs. 
Illustrated.    Just  Ready.  $3.50 

ROBINSON.  Latin  Grammar  of  Pharmacy  and  Medicine.  4th 
Edition.     With  elaborate  Vocabularies.     Just  Ready.     $1.50 

SAYRE.  Organic  Materia  Medica  and  Pharmacognosy.  An 
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Vegetable  and  Animal  Drugs.  Comprising  the  Botanical  and 
Physical  Characteristics,  Source,  Constituents,  and  Pharma- 
copeial  Preparations,  Insects  Injurious  to  Drugs,  and  Phar- 
macal  Botany.  With  sections  on  Histology  and  Microtech- 
nique, by  W.  C.  Stbvens,     374  Illustrations.    Second  Edition. 

Cloth.  $4.50 


22  SUBJECT  CAf  ALOGtJE. 

SCOVILLE.  The  Art  of  Compounding.  Second  Edition,  Re- 
vised and  Enlarged.  Cloth,  82.50 

STEWART.  Compend  of  Pharmacy.  Based  upon  "Reming- 
ton's Text-Book  of  Pharmacy."  6th  Edition,  Revised  m 
Accordance  with  the  U.  S.  Pharmacopoeia,  1890.  Complete 
Tables  of  Metric  and  English  Weights  and  Measures. 

.80;  Interleaved,  $1.00 

TAVERA.     Medicinal  Plants  of  the  Philippines.  $2.00 

UNITED  STATES  PHARMACOPCEIA.  7th  Decennial  Revision. 
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peutics.    600  Prescriptions.     9th  Edition. 

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PHYSIOLOGY. 

BIRCH.     Practical   Physiology.     An   Elementary   Class   Boole. 

62  Illustrations.  $1-75 

BRUBAKER.  Text-Book  of  Physiology.  Illus.  Nearly  Ready. 
BRUBAKER.     Compend  of  Physiology.     11th  Edition,  Revised 

and  Enlarged.     Illustrated.  .80;  Interleaved,  $1.00 

JONES.     Outlines  of  Physiology.     96  Illustrations.  $1.50 

KIRKES.  Handbook  of  Physiology.  17th  Authorized  Edition. 
Revised,  Rearranged,  and  Enlarged.  By  Prot.  W.  D.  Halli- 
burton, of  Kings  College,  London.  681  Illustrations,  some  of 
which  are  in  colors.  Cloth,  $3.00 ;  Leather,  $3.75 

LANDOIS.  A  Text-Book  of  Human  Physiology.  Including 
Histology  and  Microscopical  Anatomy,  with  Special  Reference 
to  the  Requirements  of  Practical  Medicine.  5th  American, 
translated  and  edited  from  the  last  German  Edition  by  A.  P. 
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STARLING.    Elements  of  Human  Physiology.     100  Illus.    $1.00 

STIRLING.  Outlines  of  Practical  Physiology.  Including  Chem- 
ical and  Experimental  Physiology,  with  Special  Reference  to 
Practical  Medicine.     3d  Edition.     289  Illustrations.        $2.00 

TYSON.     CeU  Doctrine.     Its  History  and  Present  State.     $1.60 

PRACTICE. 

BEALE.  On  Slight  Ailments  :  their  Nature  and  Treatment.  2d 
Edition,  Enlarged  and  Illustrated.  $1.25 

COHEN.     Physiologic  Therapeutics.     The  Treatment  of  Disease 

by  Methods  other  than  Drug-giving.     See  page  17. 

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Smith,  M.D.     2  volumes.  Vol.  I,  $6.00;  Vol.  II,  $6.00 

FOWLER.  Dictionary  of  Practical  Medicine.  By  various 
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Corners,  $1.00;  with  Thumb  Index,  $1.25. 
HUGHES.     Compend  of  the  Practice  of  Medicine.     6th  Edition, 
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Part  I.     Continued,  Eruptive,  and  Periodical  Fevers,  Disease 
of  the  Stomach,  Intestines,  Peritoneum,  Biliary  Passages, 
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vised Edition.     625  pp.     Full  Morocco,  Gilt  Edge,  $2.25 
TAYLOR.     Practice  of  Medicine.     6th  Edition.  $4.00 

TYSON.     The  Practice  of  Medicine.     By  James   Ttson,  m.ix. 
Professor  of  Medicine  in  the  University  of  Pennsylvania. 
Complete  Systematic  Text-book,  with  Special  Reference  to 
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Colored  Plates  and  125  other  Illustrations. 

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STOMACH.     INTESTINES. 

FENWICK.     Cancer  of  the  Stomach.     Just  Ready.  $3.00 

HEMMETER.  Diseases  of  the  Stomach.  Their  Special  Pathol- 
ogy, Diagnosis,  and  Treatment.  With  Sections  on  Anatomy, 
Analysis  of  Stomach  Contents,  Dietetics,  Surgery  of  the  Stom- 
ach, etc.  3d  Edition,  Revised.  With  15  Plates  and  41  other 
Illustrations,  a  number  of  which  are  in  colors. 

Cloth,  $6.00;  Sheep,  $7.00 
HEMMETER.  Diseases  of  the  Intestines.  Their  Special  Path- 
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and  Physiology,  Microscopic  and  Chemic  Examination  of  In- 
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and  many  other  Original  Illustrations.  2  volumes.  Octavo. 
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BULKLEY.     The  Skin  in  Health  and  Disease.    Illustrated.     .40 
CROCKER.     Diseases  of  the  Skin.     Their  Dejcription,  Pathol- 
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With  New  Illustrations.  Cloth,  $5.00 ;  Sheep,  $6.00 

MacLEOD.  The  Pathology  of  the  Skin.  Colored  and  other 
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lA  SUBJECT  CATALOGUE. 

SCELA.MBER6.  Diseases  of  the  Skin.  3d  Edition,  Revised  and 
Enlarged.  106  lUuBtrationa.  Beine  No.  16  ?  Qiiii-Compend? 
Series.     Jxut  Ready.  Cloth,  .80;  Interleaved,  $1.00 

VAW  HARLINGEN.  On  Skin  Diseases.  A  Practical  Manual 
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W  ential  Diagnosis.  3d  Edition,  Revised  and  Enlarged.  With 
V  Formulae  and  60  Illustrations,  some  of  which  are  printed  in 
^  colors.  $2.75 

SURGERY  AND  SURGICAL  DISEASES 
(see  also  Urinary  Organs). 

BERRY.     Diseases  of  the  Thyroid  Gland.     Illustrated.       $4.00 

BUTLIN.     Operative    Surgery    of    Malignant    Disease.    2d  Edi- 
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CASPER  AND  RICHTER.     Fimctional  Kidney  Diagnosis.  $1.50 

DAVIS.  Bandaging.  Its  Principles  and  Practice.  163  Original 
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DBAVER.  Sxirgical  Anatomy.  A  Treatise  on  Human  Anatomy 
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DULLES.  What  to  do  First  in  Accidents  and  Poisoning.  5th 
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FULLERTON.     Surgical  Nursing.     3d  Ed.     69  Illus.  $1.00 

HAMILTON.     Lectures  on  Tximors.     3d  Edition.  $1.25 

HEATH.  Minor  Surgery  and  Bandaging.  12th  Edition,  Re- 
vised and  Enlarged.  195  Illus.,  Formulae,  Diet  List,  etc.  $1.50 

HEATH.     Clinical  Lectures  on  Sxirgical  Subjects.     Second  Series. 

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HORWITZ.  Compend  of  Surgery  and  Bandaging.  Including 
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Edition,  very  much  Enlarged  and  Rearranged.  167  Illus.,  98 
Formulae.  Cloth,  .80;  Interleaved,  $1.00 

JACOBSON.  Operations  of  Surgery.  4th  Ed.,  Enlarged.  550 
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KBAY.     Medical  Treatment  of  Gall-Stones.  $1.25 

KEHR.  Gall-stone  Disease.  Translated  by  William  Wotktn* 
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MAKINS.     Surgical  Experiences  in  South  Africa.     1899-1900. 

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MAYLARD.     Surgery  of  the  Alimentary  Canal.     97  lUiistrations. 

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HOULLIN.  Text-Book  of  Surgery.  With  Special  Reference  to 
Treatment.  3d  American  Edition.  Revised  and  edited  by 
John  B.  Hamilton,  m.d.,  ll.d.,  Professor  of  the  Principles  of 
Surgery  and  Clinical  Surgery,  Rush  Medical  College,  Chicago. 
623  Illuatrations,  many  of  which  are  printed  in  colors. 

Cloth,  $6.00;  Leather,  $7.00 

SMITH.  Abdominal  Surgery.  Being  a  Systematic  Description 
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tion.    2  volumes.  Cloth,  $10.00 

VOSWTNKEL.  Surgical  Nursing.  Second  Edition,  Revised  and 
Enlarged.     Ill  Illustrations.  $1.00 

WALSHAM.  Manual  of  Practical  Surgery.  7th  Ed.,  Revised 
and  Enlarged.     483  Engravings.     950  pages.  $3.50 

TEMPERATURE  CHARTS,  ETC. 

GRIFFITH.  Graphic  Clinical  Chart  for  Recording  Tempera- 
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pation, Name,  etc.  Printed  in  three  colors.  Sample  copies 
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Two  Colored  Plates  and  80  Illustrations.  $2.75 

HOLLOPETER.     Hay  Fever.     Its  Successful  Treatment.    $1.00 

KNIGHT.  Diseases  of  the  Throat.  A  Manual  for  Students. 
Illustrated.     Just  Ready.  $3.00 

KYLE  (J.  J.).  Diseases  of  the  Ear,  Nose,  and  Throat.  A  Com- 
pend  for  Students.     Illustrated.  .§0;  Interleaved,  $1.00 

McBRIDE.  Diseases  of  the  Throat,  Nose,  and  Ear.  With  Col- 
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POTTER.  Speech  and  its  Defects.  Considered  Physiologically, 
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ACTON.  The  Functions  and  Disorders  of  the  Reproductive 
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CASPER  AND  RICHTER.   Functional  Kidney  Diagnosis.    $1.50 

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KLEEN.     Diabetes  and  Glycosuria.  $2.50 


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MEMMINGER.  Diagnosis  by  the  Urine.  2d  Edition.  24  Illus- 
trations. $1.00 

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MOULLIN.  Enlargement  of  the  Prostate.  Its  Treatment  and 
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TYSON.  Guide  to  Examination  of  the  Urine.  For  the  Use  of 
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VAIf  KUYS.     Chemical  Analysis  of  Urine.     39  Illus.  $1.00 

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JACOBSON.  The  Operations  of  Surgery.  By 
W.  H.  A.  Jacobson,  F.R.C.S.,  Surgeon  to 
Guy's  Hospital ;  Consulting  Surgeon  Royal 
Hospital  for  Children  and  Women ;  and  F. 
J.  Steward,  f.r.c.s.,  Assistant  Surgeon 
Guy's  Hospital.  Fourth  Edition — Revised, 
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Two  Volumes,  Octavo,  1524  pages. 

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"  The  important  anatomical  points  are  clearly  set  forth,  the 
conditions  indicating  or  contraindicating  operative  interference 
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forward  prominently,  and  frequently  the  after-treatment  is 
considered.  Herein  is  one  of  the  strong  points  of  the  book."— - 
Nev  York  Medical  Journal. 


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text-books  that  could  be  found  for  either  student  or  practitioner." 
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These  Compends  are  based  on  the  most  popiilar  text-books 
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revised,  so  that  they  may  thoroughly  represent  the  present  state 
of  the  subjects  upon  which  they  treat.  The  authors  have  had 
large  experience  as  Quiz-Masters  and  attaches  of  colleges,  and  are 
well  acquainted  with  the  wants  of  students.  They  are  arranged 
in  the  most  approved  form,  thorough  and  concise,  containing 
nearly  1000  illustrations  and  lithograph  plates,  inserted  wherever 
they  could  be  used  to  advantage.  Can  be  used  by  students  of 
any  coUege.  They  contain  information  nowhere  else  collected  in 
such  a  condensed,  practical  shape. 

No.  I.  POTTER.  HUMAN  ANATOMY.  Seventh  Edition.  138 
Illustrations  and  16  Plates  of  Nerves  and  Arteries. 

No.  2.  HUGHES.  PRACTICE  OF  MEDICINE.  Part  I.  Sixth 
Edition,  Enlarged  and  Improved. 

No.  3.  HUGHES.  PRACTICE  OF  MEDICINE.  Part  H.  Sixth 
Edition,  Revised  and  Improved. 

No.  4.  BRUBAKER.     PHYSIOLOGY.     Eleventh  Edition.    Illua. 

No.  5.  LANDIS.     OBSTETRICS.     Seventh    Edition.     52    Illua. 

No.  6.  POTTER.  MATERIA  MEDICA,  THERAPEUTICS,  AND 
PRESCRIPTION  WRITING.     Sixth  Revised  Edition. 

No.  7.  WELLS.     GYNECOLOGY.     Third  Edition.     140  Illus. 

No.  8.  GOULD  AND  PYLE.  DISEASES  OF  THE  EYE.  Second 
Edition.     Refraction,  Treatment,  Surgery,  etc.     109  Illus. 

No.  9.  HORWITZ.  SURGERY.  Including  Minor  Surgery, 
Bandaging,  Surgical  Diseases,  Differential  Diagnosis  and 
Treatment.  Fifth  Edition.  With  98  Formula  and  71  Illus- 
trations. 

No.  10.  LEFFMANN.  MEDICAL  CHEMISTRY.  Fourth  Edi- 
tion. Including  Urinalysis,  Animal  Chemistry,  Chemistry 
of  Milk,  Blood,  Tissues,  the  Secretions,  etc. 

No.  II.  STEWART.  PHARMACY.  Fifth  Edition.  Based  upon 
Prof.  Remington's  Text-Book  of  Pharmacy. 

No.  12.  BALLOU.  EQUINE  ANATOMY  AND  PHYSIOLOGY 
29  graphic  Illustrations. 

No.  13.  WARREN.  DENTAL  PATHOLOGY  AND  DENTAL 
MEDICINE.     Fourth  Edition,  Illustrated. 

No.  14.  HATFIELD.     DISEASES  OF  CHILDREN.     3d  Edition. 

No.  15.  THAYER.     GENERAL  PATHOLOGY.     78  Ulus. 

No.     16.  SCHAMBERG.     DISEASES    OF    THE    SKIN.     Third 
Edition,  Revised  and  Enlarged.     106  lUustrationa, 

No.  17.  GUSHING.     HISTOLOGY.     lUustrated.  In  Press. 

No.  18.  THAYER.     SPECIAL  PATHOLOGY.     34  Illustrations. 

No.  19.  KYLE.  DISEASES  OF  THE  EAR.  NOSE,  AND 
THROAT.     Illustrated. 

27 


DA  COSTA 


Clinical  Hematology 


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WITH  131ILLUSTRATIONS.    i2mo.    Cloth,  $2.00 

28 


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29 


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The  Diseases  of  the  Skin.  Their  Description,  Pathology, 
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STURGIS— MANUAL  OF 
VENEREAL  DISEASES 


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80 


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